1 00:00:09,490 --> 00:00:16,950 said that there are several theories 2 00:00:16,950 --> 00:00:16,960 said that there are several theories 3 00:00:16,960 --> 00:00:23,790 said that there are several theories which explain the bonding in molecules 4 00:00:23,790 --> 00:00:23,800 which explain the bonding in molecules 5 00:00:23,800 --> 00:00:27,120 which explain the bonding in molecules and structure and one of them was 6 00:00:27,120 --> 00:00:27,130 and structure and one of them was 7 00:00:27,130 --> 00:00:31,019 and structure and one of them was valence bond theory as we have covered 8 00:00:31,019 --> 00:00:31,029 valence bond theory as we have covered 9 00:00:31,029 --> 00:00:35,070 valence bond theory as we have covered that and the second is molecular orbital 10 00:00:35,070 --> 00:00:35,080 that and the second is molecular orbital 11 00:00:35,080 --> 00:00:38,070 that and the second is molecular orbital theory now as we said last time 12 00:00:38,070 --> 00:00:38,080 theory now as we said last time 13 00:00:38,080 --> 00:00:41,250 theory now as we said last time molecular orbital Theory simply says 14 00:00:41,250 --> 00:00:41,260 molecular orbital Theory simply says 15 00:00:41,260 --> 00:00:46,500 molecular orbital Theory simply says that the electrons in a molecule these 16 00:00:46,500 --> 00:00:46,510 that the electrons in a molecule these 17 00:00:46,510 --> 00:00:48,450 that the electrons in a molecule these are the electrons which belongs to the 18 00:00:48,450 --> 00:00:48,460 are the electrons which belongs to the 19 00:00:48,460 --> 00:00:53,280 are the electrons which belongs to the atoms that is in that molecule are found 20 00:00:53,280 --> 00:00:53,290 atoms that is in that molecule are found 21 00:00:53,290 --> 00:00:58,890 atoms that is in that molecule are found in molecular orbitals just like in an 22 00:00:58,890 --> 00:00:58,900 in molecular orbitals just like in an 23 00:00:58,900 --> 00:01:02,189 in molecular orbitals just like in an atom the electrons are found in atomic 24 00:01:02,189 --> 00:01:02,199 atom the electrons are found in atomic 25 00:01:02,199 --> 00:01:06,840 atom the electrons are found in atomic orbital those are spdf orbitals and so 26 00:01:06,840 --> 00:01:06,850 orbital those are spdf orbitals and so 27 00:01:06,850 --> 00:01:12,330 orbital those are spdf orbitals and so on but in the molecule the electron goes 28 00:01:12,330 --> 00:01:12,340 on but in the molecule the electron goes 29 00:01:12,340 --> 00:01:15,749 on but in the molecule the electron goes in to the molecular orbitals now what 30 00:01:15,749 --> 00:01:15,759 in to the molecular orbitals now what 31 00:01:15,759 --> 00:01:18,139 in to the molecular orbitals now what are these molecular orbitals and how we 32 00:01:18,139 --> 00:01:18,149 are these molecular orbitals and how we 33 00:01:18,149 --> 00:01:21,300 are these molecular orbitals and how we construct those we said that the 34 00:01:21,300 --> 00:01:21,310 construct those we said that the 35 00:01:21,310 --> 00:01:24,779 construct those we said that the molecular orbitals are simply obtained 36 00:01:24,779 --> 00:01:24,789 molecular orbitals are simply obtained 37 00:01:24,789 --> 00:01:28,200 molecular orbitals are simply obtained by linear combinations of the atomic 38 00:01:28,200 --> 00:01:28,210 by linear combinations of the atomic 39 00:01:28,210 --> 00:01:31,709 by linear combinations of the atomic orbitals of the atoms that present in 40 00:01:31,709 --> 00:01:31,719 orbitals of the atoms that present in 41 00:01:31,719 --> 00:01:36,959 orbitals of the atoms that present in that molecule now the shape of these 42 00:01:36,959 --> 00:01:36,969 that molecule now the shape of these 43 00:01:36,969 --> 00:01:39,599 that molecule now the shape of these molecular orbitals are different than 44 00:01:39,599 --> 00:01:39,609 molecular orbitals are different than 45 00:01:39,609 --> 00:01:42,989 molecular orbitals are different than the atomic orbitals actually and they 46 00:01:42,989 --> 00:01:42,999 the atomic orbitals actually and they 47 00:01:42,999 --> 00:01:50,969 the atomic orbitals actually and they expand overall molecule and when you 48 00:01:50,969 --> 00:01:50,979 expand overall molecule and when you 49 00:01:50,979 --> 00:01:57,179 expand overall molecule and when you simply put the electrons into these 50 00:01:57,179 --> 00:01:57,189 simply put the electrons into these 51 00:01:57,189 --> 00:01:58,410 simply put the electrons into these molecular orbitals 52 00:01:58,410 --> 00:01:58,420 molecular orbitals 53 00:01:58,420 --> 00:02:02,789 molecular orbitals just like in Otto McQuarrie tools every 54 00:02:02,789 --> 00:02:02,799 just like in Otto McQuarrie tools every 55 00:02:02,799 --> 00:02:06,510 just like in Otto McQuarrie tools every molecular orbital can accommodate two 56 00:02:06,510 --> 00:02:06,520 molecular orbital can accommodate two 57 00:02:06,520 --> 00:02:10,109 molecular orbital can accommodate two electrons maximum and the spin off these 58 00:02:10,109 --> 00:02:10,119 electrons maximum and the spin off these 59 00:02:10,119 --> 00:02:12,510 electrons maximum and the spin off these two electrons have to be opposite to 60 00:02:12,510 --> 00:02:12,520 two electrons have to be opposite to 61 00:02:12,520 --> 00:02:15,350 two electrons have to be opposite to each other that means that the electrons 62 00:02:15,350 --> 00:02:15,360 each other that means that the electrons 63 00:02:15,360 --> 00:02:17,820 each other that means that the electrons two electrons in a molecular orbital 64 00:02:17,820 --> 00:02:17,830 two electrons in a molecular orbital 65 00:02:17,830 --> 00:02:21,620 two electrons in a molecular orbital will be paired spin paired 66 00:02:21,620 --> 00:02:21,630 will be paired spin paired 67 00:02:21,630 --> 00:02:27,350 will be paired spin paired and any electron simply goes into the 68 00:02:27,350 --> 00:02:27,360 and any electron simply goes into the 69 00:02:27,360 --> 00:02:32,230 and any electron simply goes into the Mallick bonding molecular orbital 70 00:02:32,230 --> 00:02:32,240 71 00:02:32,240 --> 00:02:35,630 stabilizes the molecule any electron 72 00:02:35,630 --> 00:02:35,640 stabilizes the molecule any electron 73 00:02:35,640 --> 00:02:37,790 stabilizes the molecule any electron that goes into the anti-bonding 74 00:02:37,790 --> 00:02:37,800 that goes into the anti-bonding 75 00:02:37,800 --> 00:02:41,330 that goes into the anti-bonding molecular orbitals DC stabilizes the 76 00:02:41,330 --> 00:02:41,340 molecular orbitals DC stabilizes the 77 00:02:41,340 --> 00:02:46,220 molecular orbitals DC stabilizes the electron this stabilizes the molecule so 78 00:02:46,220 --> 00:02:46,230 electron this stabilizes the molecule so 79 00:02:46,230 --> 00:02:49,070 electron this stabilizes the molecule so again there are two kinds of molecular 80 00:02:49,070 --> 00:02:49,080 again there are two kinds of molecular 81 00:02:49,080 --> 00:02:52,390 again there are two kinds of molecular orbitals bonding molecular orbitals 82 00:02:52,390 --> 00:02:52,400 orbitals bonding molecular orbitals 83 00:02:52,400 --> 00:02:55,670 orbitals bonding molecular orbitals anti-bonding molecular orbitals actually 84 00:02:55,670 --> 00:02:55,680 anti-bonding molecular orbitals actually 85 00:02:55,680 --> 00:02:58,430 anti-bonding molecular orbitals actually when you combine linearly combine two 86 00:02:58,430 --> 00:02:58,440 when you combine linearly combine two 87 00:02:58,440 --> 00:03:01,430 when you combine linearly combine two atomic orbitals in a molecule you will 88 00:03:01,430 --> 00:03:01,440 atomic orbitals in a molecule you will 89 00:03:01,440 --> 00:03:03,860 atomic orbitals in a molecule you will get you will end up with two molecular 90 00:03:03,860 --> 00:03:03,870 get you will end up with two molecular 91 00:03:03,870 --> 00:03:06,200 get you will end up with two molecular orbitals one will be binding the other 92 00:03:06,200 --> 00:03:06,210 orbitals one will be binding the other 93 00:03:06,210 --> 00:03:09,320 orbitals one will be binding the other one will be anti-bonding any electron 94 00:03:09,320 --> 00:03:09,330 one will be anti-bonding any electron 95 00:03:09,330 --> 00:03:11,810 one will be anti-bonding any electron again as it goes into the bonding 96 00:03:11,810 --> 00:03:11,820 again as it goes into the bonding 97 00:03:11,820 --> 00:03:13,370 again as it goes into the bonding molecular orbital which is lower in 98 00:03:13,370 --> 00:03:13,380 molecular orbital which is lower in 99 00:03:13,380 --> 00:03:17,240 molecular orbital which is lower in energy that simply stabilizes the 100 00:03:17,240 --> 00:03:17,250 energy that simply stabilizes the 101 00:03:17,250 --> 00:03:20,900 energy that simply stabilizes the molecule means that it binds the atoms 102 00:03:20,900 --> 00:03:20,910 molecule means that it binds the atoms 103 00:03:20,910 --> 00:03:22,250 molecule means that it binds the atoms in the molecule together 104 00:03:22,250 --> 00:03:22,260 in the molecule together 105 00:03:22,260 --> 00:03:28,280 in the molecule together therefore the electrons which are in 106 00:03:28,280 --> 00:03:28,290 therefore the electrons which are in 107 00:03:28,290 --> 00:03:30,920 therefore the electrons which are in bonding molecular orbitals are found 108 00:03:30,920 --> 00:03:30,930 bonding molecular orbitals are found 109 00:03:30,930 --> 00:03:35,240 bonding molecular orbitals are found between the nuclei of the two atoms sort 110 00:03:35,240 --> 00:03:35,250 between the nuclei of the two atoms sort 111 00:03:35,250 --> 00:03:39,920 between the nuclei of the two atoms sort of they simply concentrate increase 112 00:03:39,920 --> 00:03:39,930 of they simply concentrate increase 113 00:03:39,930 --> 00:03:43,730 of they simply concentrate increase their intensity density between the 114 00:03:43,730 --> 00:03:43,740 their intensity density between the 115 00:03:43,740 --> 00:03:47,090 their intensity density between the nuclei if any electron goes into 116 00:03:47,090 --> 00:03:47,100 nuclei if any electron goes into 117 00:03:47,100 --> 00:03:50,690 nuclei if any electron goes into anti-bonding then they will be sort of 118 00:03:50,690 --> 00:03:50,700 anti-bonding then they will be sort of 119 00:03:50,700 --> 00:03:55,940 anti-bonding then they will be sort of out of the inter nuclear volume they 120 00:03:55,940 --> 00:03:55,950 out of the inter nuclear volume they 121 00:03:55,950 --> 00:03:58,310 out of the inter nuclear volume they will be out from there and they 122 00:03:58,310 --> 00:03:58,320 will be out from there and they 123 00:03:58,320 --> 00:04:01,030 will be out from there and they destabilize actually as it says 124 00:04:01,030 --> 00:04:01,040 destabilize actually as it says 125 00:04:01,040 --> 00:04:04,580 destabilize actually as it says anti-bonding destabilizes the overall 126 00:04:04,580 --> 00:04:04,590 anti-bonding destabilizes the overall 127 00:04:04,590 --> 00:04:10,280 anti-bonding destabilizes the overall molecule okay as we showed last time if 128 00:04:10,280 --> 00:04:10,290 molecule okay as we showed last time if 129 00:04:10,290 --> 00:04:14,390 molecule okay as we showed last time if we simply look at how these molecular 130 00:04:14,390 --> 00:04:14,400 we simply look at how these molecular 131 00:04:14,400 --> 00:04:16,010 we simply look at how these molecular orbitals would look like in 132 00:04:16,010 --> 00:04:16,020 orbitals would look like in 133 00:04:16,020 --> 00:04:19,729 orbitals would look like in three-dimensional space here the example 134 00:04:19,729 --> 00:04:19,739 three-dimensional space here the example 135 00:04:19,739 --> 00:04:23,330 three-dimensional space here the example when you have hydrogen molecule so you 136 00:04:23,330 --> 00:04:23,340 when you have hydrogen molecule so you 137 00:04:23,340 --> 00:04:28,040 when you have hydrogen molecule so you combine 1s orbitals of one hydrogen and 138 00:04:28,040 --> 00:04:28,050 combine 1s orbitals of one hydrogen and 139 00:04:28,050 --> 00:04:30,950 combine 1s orbitals of one hydrogen and with the 1s orbitals of the other 140 00:04:30,950 --> 00:04:30,960 with the 1s orbitals of the other 141 00:04:30,960 --> 00:04:34,100 with the 1s orbitals of the other hydrogen and when those two combines 142 00:04:34,100 --> 00:04:34,110 hydrogen and when those two combines 143 00:04:34,110 --> 00:04:35,510 hydrogen and when those two combines linearly actually 144 00:04:35,510 --> 00:04:35,520 linearly actually 145 00:04:35,520 --> 00:04:39,230 linearly actually two atomic orbitals we get two molecular 146 00:04:39,230 --> 00:04:39,240 two atomic orbitals we get two molecular 147 00:04:39,240 --> 00:04:41,870 two atomic orbitals we get two molecular orbitals this is the bonding molecular 148 00:04:41,870 --> 00:04:41,880 orbitals this is the bonding molecular 149 00:04:41,880 --> 00:04:44,629 orbitals this is the bonding molecular orbitals this is the nth abandoned 150 00:04:44,629 --> 00:04:44,639 orbitals this is the nth abandoned 151 00:04:44,639 --> 00:04:47,270 orbitals this is the nth abandoned molecular orbitals so any electron that 152 00:04:47,270 --> 00:04:47,280 molecular orbitals so any electron that 153 00:04:47,280 --> 00:04:49,339 molecular orbitals so any electron that goes into the bonding molecular orbiters 154 00:04:49,339 --> 00:04:49,349 goes into the bonding molecular orbiters 155 00:04:49,349 --> 00:04:51,980 goes into the bonding molecular orbiters spend more time between the nuclei of 156 00:04:51,980 --> 00:04:51,990 spend more time between the nuclei of 157 00:04:51,990 --> 00:04:53,689 spend more time between the nuclei of these two atoms between two hydrogen 158 00:04:53,689 --> 00:04:53,699 these two atoms between two hydrogen 159 00:04:53,699 --> 00:04:56,059 these two atoms between two hydrogen nuclei that means that electron 160 00:04:56,059 --> 00:04:56,069 nuclei that means that electron 161 00:04:56,069 --> 00:04:58,790 nuclei that means that electron corresponds to shared by the two atoms 162 00:04:58,790 --> 00:04:58,800 corresponds to shared by the two atoms 163 00:04:58,800 --> 00:05:03,110 corresponds to shared by the two atoms and simply stabilizes the hydrogen 164 00:05:03,110 --> 00:05:03,120 and simply stabilizes the hydrogen 165 00:05:03,120 --> 00:05:06,740 and simply stabilizes the hydrogen molecule or binds the hydrogen atoms 166 00:05:06,740 --> 00:05:06,750 molecule or binds the hydrogen atoms 167 00:05:06,750 --> 00:05:09,200 molecule or binds the hydrogen atoms together in the molecule and an electron 168 00:05:09,200 --> 00:05:09,210 together in the molecule and an electron 169 00:05:09,210 --> 00:05:10,969 together in the molecule and an electron goes into the anti-bonding which looks 170 00:05:10,969 --> 00:05:10,979 goes into the anti-bonding which looks 171 00:05:10,979 --> 00:05:12,020 goes into the anti-bonding which looks like this again this is 172 00:05:12,020 --> 00:05:12,030 like this again this is 173 00:05:12,030 --> 00:05:14,330 like this again this is three-dimensional remember and the 174 00:05:14,330 --> 00:05:14,340 three-dimensional remember and the 175 00:05:14,340 --> 00:05:18,110 three-dimensional remember and the electron density more out of the inter 176 00:05:18,110 --> 00:05:18,120 electron density more out of the inter 177 00:05:18,120 --> 00:05:22,760 electron density more out of the inter nuclear volume here sort of out here 178 00:05:22,760 --> 00:05:22,770 nuclear volume here sort of out here 179 00:05:22,770 --> 00:05:26,420 nuclear volume here sort of out here there actually there is a plane where 180 00:05:26,420 --> 00:05:26,430 there actually there is a plane where 181 00:05:26,430 --> 00:05:29,360 there actually there is a plane where the probability of finding the electron 182 00:05:29,360 --> 00:05:29,370 the probability of finding the electron 183 00:05:29,370 --> 00:05:32,029 the probability of finding the electron is zero that's we call the nodal plane 184 00:05:32,029 --> 00:05:32,039 is zero that's we call the nodal plane 185 00:05:32,039 --> 00:05:36,409 is zero that's we call the nodal plane in fact between the two nuclei now how 186 00:05:36,409 --> 00:05:36,419 in fact between the two nuclei now how 187 00:05:36,419 --> 00:05:39,230 in fact between the two nuclei now how about the again here as we said last 188 00:05:39,230 --> 00:05:39,240 about the again here as we said last 189 00:05:39,240 --> 00:05:41,629 about the again here as we said last time and when you consider the symmetry 190 00:05:41,629 --> 00:05:41,639 time and when you consider the symmetry 191 00:05:41,639 --> 00:05:44,779 time and when you consider the symmetry of these two molecular orbitals 192 00:05:44,779 --> 00:05:44,789 of these two molecular orbitals 193 00:05:44,789 --> 00:05:47,990 of these two molecular orbitals both have Sigma symmetry what does that 194 00:05:47,990 --> 00:05:48,000 both have Sigma symmetry what does that 195 00:05:48,000 --> 00:05:49,870 both have Sigma symmetry what does that means again as we have seen it before 196 00:05:49,870 --> 00:05:49,880 means again as we have seen it before 197 00:05:49,880 --> 00:05:53,390 means again as we have seen it before Sigma symmetry means that the orbital 198 00:05:53,390 --> 00:05:53,400 Sigma symmetry means that the orbital 199 00:05:53,400 --> 00:05:57,909 Sigma symmetry means that the orbital have have rotational symmetry around the 200 00:05:57,909 --> 00:05:57,919 have have rotational symmetry around the 201 00:05:57,919 --> 00:06:01,300 have have rotational symmetry around the bond axis bond taxes which binds the two 202 00:06:01,300 --> 00:06:01,310 bond axis bond taxes which binds the two 203 00:06:01,310 --> 00:06:05,809 bond axis bond taxes which binds the two we call that Sigma type indicating just 204 00:06:05,809 --> 00:06:05,819 we call that Sigma type indicating just 205 00:06:05,819 --> 00:06:08,779 we call that Sigma type indicating just the symmetry both of these are Sigma 206 00:06:08,779 --> 00:06:08,789 the symmetry both of these are Sigma 207 00:06:08,789 --> 00:06:12,080 the symmetry both of these are Sigma type orbitals molecular orbitals and 208 00:06:12,080 --> 00:06:12,090 type orbitals molecular orbitals and 209 00:06:12,090 --> 00:06:16,909 type orbitals molecular orbitals and this is called as Sigma 1 as simply just 210 00:06:16,909 --> 00:06:16,919 this is called as Sigma 1 as simply just 211 00:06:16,919 --> 00:06:20,029 this is called as Sigma 1 as simply just the notation which tells us that one s 212 00:06:20,029 --> 00:06:20,039 the notation which tells us that one s 213 00:06:20,039 --> 00:06:22,909 the notation which tells us that one s orbital combine to form this bond and 214 00:06:22,909 --> 00:06:22,919 orbital combine to form this bond and 215 00:06:22,919 --> 00:06:24,620 orbital combine to form this bond and molecular orbitals and this is the 216 00:06:24,620 --> 00:06:24,630 molecular orbitals and this is the 217 00:06:24,630 --> 00:06:26,719 molecular orbitals and this is the anti-bonding molecular orbital again 218 00:06:26,719 --> 00:06:26,729 anti-bonding molecular orbital again 219 00:06:26,729 --> 00:06:29,689 anti-bonding molecular orbital again Sigma 1s but we put a star there and 220 00:06:29,689 --> 00:06:29,699 Sigma 1s but we put a star there and 221 00:06:29,699 --> 00:06:33,649 Sigma 1s but we put a star there and that star means its anti-bonding now how 222 00:06:33,649 --> 00:06:33,659 that star means its anti-bonding now how 223 00:06:33,659 --> 00:06:36,499 that star means its anti-bonding now how about the energies of these molecular 224 00:06:36,499 --> 00:06:36,509 about the energies of these molecular 225 00:06:36,509 --> 00:06:39,589 about the energies of these molecular orbitals with respect to the energies of 226 00:06:39,589 --> 00:06:39,599 orbitals with respect to the energies of 227 00:06:39,599 --> 00:06:45,589 orbitals with respect to the energies of the atomic orbitals and this is again 228 00:06:45,589 --> 00:06:45,599 the atomic orbitals and this is again 229 00:06:45,599 --> 00:06:48,110 the atomic orbitals and this is again what we call molecular orbital energy 230 00:06:48,110 --> 00:06:48,120 what we call molecular orbital energy 231 00:06:48,120 --> 00:06:48,770 what we call molecular orbital energy level 232 00:06:48,770 --> 00:06:48,780 level 233 00:06:48,780 --> 00:06:52,550 level diagram indicates the molecular orbital 234 00:06:52,550 --> 00:06:52,560 diagram indicates the molecular orbital 235 00:06:52,560 --> 00:06:54,140 diagram indicates the molecular orbital relative energy is off the molecular 236 00:06:54,140 --> 00:06:54,150 relative energy is off the molecular 237 00:06:54,150 --> 00:06:56,060 relative energy is off the molecular orbital and this is the bonding 238 00:06:56,060 --> 00:06:56,070 orbital and this is the bonding 239 00:06:56,070 --> 00:06:58,070 orbital and this is the bonding molecular orbital this is the end tie 240 00:06:58,070 --> 00:06:58,080 molecular orbital this is the end tie 241 00:06:58,080 --> 00:07:00,650 molecular orbital this is the end tie bonding molecular orbital these are the 242 00:07:00,650 --> 00:07:00,660 bonding molecular orbital these are the 243 00:07:00,660 --> 00:07:03,470 bonding molecular orbital these are the 1s atomic orbitals and one SF atomic 244 00:07:03,470 --> 00:07:03,480 1s atomic orbitals and one SF atomic 245 00:07:03,480 --> 00:07:05,930 1s atomic orbitals and one SF atomic orbitals again you see as we said last 246 00:07:05,930 --> 00:07:05,940 orbitals again you see as we said last 247 00:07:05,940 --> 00:07:09,830 orbitals again you see as we said last time when you have hydrogen molecule you 248 00:07:09,830 --> 00:07:09,840 time when you have hydrogen molecule you 249 00:07:09,840 --> 00:07:11,690 time when you have hydrogen molecule you form a hydrogen molecule from two 250 00:07:11,690 --> 00:07:11,700 form a hydrogen molecule from two 251 00:07:11,700 --> 00:07:15,020 form a hydrogen molecule from two hydrogen atoms the electron will go from 252 00:07:15,020 --> 00:07:15,030 hydrogen atoms the electron will go from 253 00:07:15,030 --> 00:07:18,770 hydrogen atoms the electron will go from this one s level to the Sigma 1s 254 00:07:18,770 --> 00:07:18,780 this one s level to the Sigma 1s 255 00:07:18,780 --> 00:07:20,990 this one s level to the Sigma 1s molecular orbital binding molecular 256 00:07:20,990 --> 00:07:21,000 molecular orbital binding molecular 257 00:07:21,000 --> 00:07:23,030 molecular orbital binding molecular orbital and this one will also go there 258 00:07:23,030 --> 00:07:23,040 orbital and this one will also go there 259 00:07:23,040 --> 00:07:24,740 orbital and this one will also go there that simply means when you put the 260 00:07:24,740 --> 00:07:24,750 that simply means when you put the 261 00:07:24,750 --> 00:07:27,710 that simply means when you put the electron from this level to there that 262 00:07:27,710 --> 00:07:27,720 electron from this level to there that 263 00:07:27,720 --> 00:07:29,810 electron from this level to there that much energy will be released so if you 264 00:07:29,810 --> 00:07:29,820 much energy will be released so if you 265 00:07:29,820 --> 00:07:32,000 much energy will be released so if you put two electrons there that means two 266 00:07:32,000 --> 00:07:32,010 put two electrons there that means two 267 00:07:32,010 --> 00:07:34,280 put two electrons there that means two times of that much energy is released to 268 00:07:34,280 --> 00:07:34,290 times of that much energy is released to 269 00:07:34,290 --> 00:07:36,350 times of that much energy is released to the surrounding means that much the 270 00:07:36,350 --> 00:07:36,360 the surrounding means that much the 271 00:07:36,360 --> 00:07:40,280 the surrounding means that much the molecule become more stable right the 272 00:07:40,280 --> 00:07:40,290 molecule become more stable right the 273 00:07:40,290 --> 00:07:43,460 molecule become more stable right the molecule become more stable so again as 274 00:07:43,460 --> 00:07:43,470 molecule become more stable so again as 275 00:07:43,470 --> 00:07:47,420 molecule become more stable so again as we have described last time when we have 276 00:07:47,420 --> 00:07:47,430 we have described last time when we have 277 00:07:47,430 --> 00:07:49,490 we have described last time when we have the molecular orbital energy level 278 00:07:49,490 --> 00:07:49,500 the molecular orbital energy level 279 00:07:49,500 --> 00:07:52,630 the molecular orbital energy level diagram we can simply write down the 280 00:07:52,630 --> 00:07:52,640 diagram we can simply write down the 281 00:07:52,640 --> 00:07:56,300 diagram we can simply write down the bond order for that molecule now 282 00:07:56,300 --> 00:07:56,310 bond order for that molecule now 283 00:07:56,310 --> 00:07:59,240 bond order for that molecule now remember again when we say bond order 284 00:07:59,240 --> 00:07:59,250 remember again when we say bond order 285 00:07:59,250 --> 00:08:01,790 remember again when we say bond order that is for the molecule it's not for 286 00:08:01,790 --> 00:08:01,800 that is for the molecule it's not for 287 00:08:01,800 --> 00:08:04,219 that is for the molecule it's not for the atoms in this case since we have two 288 00:08:04,219 --> 00:08:04,229 the atoms in this case since we have two 289 00:08:04,229 --> 00:08:06,650 the atoms in this case since we have two atoms we just that will be the bond 290 00:08:06,650 --> 00:08:06,660 atoms we just that will be the bond 291 00:08:06,660 --> 00:08:09,560 atoms we just that will be the bond order for between for the two hydrogen 292 00:08:09,560 --> 00:08:09,570 order for between for the two hydrogen 293 00:08:09,570 --> 00:08:12,620 order for between for the two hydrogen atoms actually but the bond order is for 294 00:08:12,620 --> 00:08:12,630 atoms actually but the bond order is for 295 00:08:12,630 --> 00:08:14,990 atoms actually but the bond order is for the whole molecule once we have the 296 00:08:14,990 --> 00:08:15,000 the whole molecule once we have the 297 00:08:15,000 --> 00:08:17,510 the whole molecule once we have the molecular orbital of a molecule that 298 00:08:17,510 --> 00:08:17,520 molecular orbital of a molecule that 299 00:08:17,520 --> 00:08:20,330 molecular orbital of a molecule that means we know how many electron goes 300 00:08:20,330 --> 00:08:20,340 means we know how many electron goes 301 00:08:20,340 --> 00:08:21,920 means we know how many electron goes into the bonding orbital how many 302 00:08:21,920 --> 00:08:21,930 into the bonding orbital how many 303 00:08:21,930 --> 00:08:23,090 into the bonding orbital how many electron goes into the anti-bonding 304 00:08:23,090 --> 00:08:23,100 electron goes into the anti-bonding 305 00:08:23,100 --> 00:08:25,760 electron goes into the anti-bonding orbital we can calculate the bond order 306 00:08:25,760 --> 00:08:25,770 orbital we can calculate the bond order 307 00:08:25,770 --> 00:08:28,610 orbital we can calculate the bond order using this formula simply the number of 308 00:08:28,610 --> 00:08:28,620 using this formula simply the number of 309 00:08:28,620 --> 00:08:30,710 using this formula simply the number of electrons in bonding molecular orbital 310 00:08:30,710 --> 00:08:30,720 electrons in bonding molecular orbital 311 00:08:30,720 --> 00:08:33,320 electrons in bonding molecular orbital bonding simply means lower energy than 312 00:08:33,320 --> 00:08:33,330 bonding simply means lower energy than 313 00:08:33,330 --> 00:08:36,800 bonding simply means lower energy than these two over here and minus the number 314 00:08:36,800 --> 00:08:36,810 these two over here and minus the number 315 00:08:36,810 --> 00:08:39,260 these two over here and minus the number of electrons in anti-bonding divided by 316 00:08:39,260 --> 00:08:39,270 of electrons in anti-bonding divided by 317 00:08:39,270 --> 00:08:42,380 of electrons in anti-bonding divided by two and that gives us the bond order one 318 00:08:42,380 --> 00:08:42,390 two and that gives us the bond order one 319 00:08:42,390 --> 00:08:49,570 two and that gives us the bond order one in this case actually two minus zero one 320 00:08:49,570 --> 00:08:49,580 321 00:08:49,580 --> 00:08:56,120 now when we have helium molecule let's 322 00:08:56,120 --> 00:08:56,130 now when we have helium molecule let's 323 00:08:56,130 --> 00:08:58,520 now when we have helium molecule let's consider the helium molecule remember 324 00:08:58,520 --> 00:08:58,530 consider the helium molecule remember 325 00:08:58,530 --> 00:09:01,870 consider the helium molecule remember the helium molecule has two 326 00:09:01,870 --> 00:09:01,880 the helium molecule has two 327 00:09:01,880 --> 00:09:05,920 the helium molecule has two helium atom has two electrons and the 328 00:09:05,920 --> 00:09:05,930 helium atom has two electrons and the 329 00:09:05,930 --> 00:09:10,260 helium atom has two electrons and the electron structure is 1s2 this is the 330 00:09:10,260 --> 00:09:10,270 electron structure is 1s2 this is the 331 00:09:10,270 --> 00:09:14,370 electron structure is 1s2 this is the simply electron configuration of helium 332 00:09:14,370 --> 00:09:14,380 simply electron configuration of helium 333 00:09:14,380 --> 00:09:17,650 simply electron configuration of helium atom so when you combine two helium 334 00:09:17,650 --> 00:09:17,660 atom so when you combine two helium 335 00:09:17,660 --> 00:09:22,030 atom so when you combine two helium atoms just like hydrogen atoms to form a 336 00:09:22,030 --> 00:09:22,040 atoms just like hydrogen atoms to form a 337 00:09:22,040 --> 00:09:25,750 atoms just like hydrogen atoms to form a helium molecule and show the molecular 338 00:09:25,750 --> 00:09:25,760 helium molecule and show the molecular 339 00:09:25,760 --> 00:09:28,840 helium molecule and show the molecular orbitals there again we will have the 340 00:09:28,840 --> 00:09:28,850 orbitals there again we will have the 341 00:09:28,850 --> 00:09:31,050 orbitals there again we will have the bonding molecular orbital and 342 00:09:31,050 --> 00:09:31,060 bonding molecular orbital and 343 00:09:31,060 --> 00:09:33,820 bonding molecular orbital and anti-bonding molecular orbital exactly 344 00:09:33,820 --> 00:09:33,830 anti-bonding molecular orbital exactly 345 00:09:33,830 --> 00:09:37,330 anti-bonding molecular orbital exactly the same as the hydrogen molecule the 346 00:09:37,330 --> 00:09:37,340 the same as the hydrogen molecule the 347 00:09:37,340 --> 00:09:39,670 the same as the hydrogen molecule the only difference is remember since the 348 00:09:39,670 --> 00:09:39,680 only difference is remember since the 349 00:09:39,680 --> 00:09:43,390 only difference is remember since the helium has two protons hydrogen has one 350 00:09:43,390 --> 00:09:43,400 helium has two protons hydrogen has one 351 00:09:43,400 --> 00:09:46,990 helium has two protons hydrogen has one proton the energies of these 1s orbital 352 00:09:46,990 --> 00:09:47,000 proton the energies of these 1s orbital 353 00:09:47,000 --> 00:09:49,590 proton the energies of these 1s orbital in helium and hydrogen will be different 354 00:09:49,590 --> 00:09:49,600 in helium and hydrogen will be different 355 00:09:49,600 --> 00:09:52,870 in helium and hydrogen will be different right and in the case of helium will be 356 00:09:52,870 --> 00:09:52,880 right and in the case of helium will be 357 00:09:52,880 --> 00:09:55,000 right and in the case of helium will be more stable or less stable than the 358 00:09:55,000 --> 00:09:55,010 more stable or less stable than the 359 00:09:55,010 --> 00:09:58,990 more stable or less stable than the hydrogen more stable because we have two 360 00:09:58,990 --> 00:09:59,000 hydrogen more stable because we have two 361 00:09:59,000 --> 00:10:02,170 hydrogen more stable because we have two protons Z effective actually for those 362 00:10:02,170 --> 00:10:02,180 protons Z effective actually for those 363 00:10:02,180 --> 00:10:06,150 protons Z effective actually for those electrons will be higher and more stable 364 00:10:06,150 --> 00:10:06,160 electrons will be higher and more stable 365 00:10:06,160 --> 00:10:09,970 electrons will be higher and more stable that's the only difference we can simply 366 00:10:09,970 --> 00:10:09,980 that's the only difference we can simply 367 00:10:09,980 --> 00:10:11,980 that's the only difference we can simply other than the number of electrons 368 00:10:11,980 --> 00:10:11,990 other than the number of electrons 369 00:10:11,990 --> 00:10:14,650 other than the number of electrons between the helium atoms and the 370 00:10:14,650 --> 00:10:14,660 between the helium atoms and the 371 00:10:14,660 --> 00:10:19,360 between the helium atoms and the hydrogen atoms so we have again 1s 372 00:10:19,360 --> 00:10:19,370 hydrogen atoms so we have again 1s 373 00:10:19,370 --> 00:10:22,060 hydrogen atoms so we have again 1s orbital just the same shape similar 374 00:10:22,060 --> 00:10:22,070 orbital just the same shape similar 375 00:10:22,070 --> 00:10:26,440 orbital just the same shape similar Sigma type simply as the hydrogen 376 00:10:26,440 --> 00:10:26,450 Sigma type simply as the hydrogen 377 00:10:26,450 --> 00:10:29,140 Sigma type simply as the hydrogen molecule bonding molecular orbital Sigma 378 00:10:29,140 --> 00:10:29,150 molecule bonding molecular orbital Sigma 379 00:10:29,150 --> 00:10:32,350 molecule bonding molecular orbital Sigma 1s and anti-bonding molecular orbital 380 00:10:32,350 --> 00:10:32,360 1s and anti-bonding molecular orbital 381 00:10:32,360 --> 00:10:32,890 1s and anti-bonding molecular orbital Sigma 1s 382 00:10:32,890 --> 00:10:32,900 Sigma 1s 383 00:10:32,900 --> 00:10:36,280 Sigma 1s now since we have two electrons coming 384 00:10:36,280 --> 00:10:36,290 now since we have two electrons coming 385 00:10:36,290 --> 00:10:39,790 now since we have two electrons coming from each helium atoms so we have to put 386 00:10:39,790 --> 00:10:39,800 from each helium atoms so we have to put 387 00:10:39,800 --> 00:10:41,890 from each helium atoms so we have to put those electrons into the molecular 388 00:10:41,890 --> 00:10:41,900 those electrons into the molecular 389 00:10:41,900 --> 00:10:43,870 those electrons into the molecular orbitals this is the molecule actually 390 00:10:43,870 --> 00:10:43,880 orbitals this is the molecule actually 391 00:10:43,880 --> 00:10:46,000 orbitals this is the molecule actually these are separate atoms infinitely 392 00:10:46,000 --> 00:10:46,010 these are separate atoms infinitely 393 00:10:46,010 --> 00:10:48,850 these are separate atoms infinitely apart so we put two Maalik two electrons 394 00:10:48,850 --> 00:10:48,860 apart so we put two Maalik two electrons 395 00:10:48,860 --> 00:10:51,730 apart so we put two Maalik two electrons here in bonding molecular orbital and we 396 00:10:51,730 --> 00:10:51,740 here in bonding molecular orbital and we 397 00:10:51,740 --> 00:10:54,070 here in bonding molecular orbital and we will put the other two in anti-bonding 398 00:10:54,070 --> 00:10:54,080 will put the other two in anti-bonding 399 00:10:54,080 --> 00:10:56,790 will put the other two in anti-bonding molecular orbital now what will happen 400 00:10:56,790 --> 00:10:56,800 molecular orbital now what will happen 401 00:10:56,800 --> 00:10:58,810 molecular orbital now what will happen energetically if you look at the energy 402 00:10:58,810 --> 00:10:58,820 energetically if you look at the energy 403 00:10:58,820 --> 00:11:02,020 energetically if you look at the energy wise when you put two electrons to the 404 00:11:02,020 --> 00:11:02,030 wise when you put two electrons to the 405 00:11:02,030 --> 00:11:04,150 wise when you put two electrons to the bonding molecular orbitals that means 406 00:11:04,150 --> 00:11:04,160 bonding molecular orbitals that means 407 00:11:04,160 --> 00:11:06,910 bonding molecular orbitals that means that the helium molecules stabilised 408 00:11:06,910 --> 00:11:06,920 that the helium molecules stabilised 409 00:11:06,920 --> 00:11:10,990 that the helium molecules stabilised twice as much energy here this twice as 410 00:11:10,990 --> 00:11:11,000 twice as much energy here this twice as 411 00:11:11,000 --> 00:11:13,150 twice as much energy here this twice as that because that much energy is 412 00:11:13,150 --> 00:11:13,160 that because that much energy is 413 00:11:13,160 --> 00:11:14,740 that because that much energy is released when you put one electron there 414 00:11:14,740 --> 00:11:14,750 released when you put one electron there 415 00:11:14,750 --> 00:11:15,310 released when you put one electron there another elec 416 00:11:15,310 --> 00:11:15,320 another elec 417 00:11:15,320 --> 00:11:17,170 another elec they're that much energy is released it 418 00:11:17,170 --> 00:11:17,180 they're that much energy is released it 419 00:11:17,180 --> 00:11:19,720 they're that much energy is released it becomes stable but on the other side 420 00:11:19,720 --> 00:11:19,730 becomes stable but on the other side 421 00:11:19,730 --> 00:11:22,180 becomes stable but on the other side when you take one electron and put it in 422 00:11:22,180 --> 00:11:22,190 when you take one electron and put it in 423 00:11:22,190 --> 00:11:26,770 when you take one electron and put it in higher energy level put it in the Sigma 424 00:11:26,770 --> 00:11:26,780 higher energy level put it in the Sigma 425 00:11:26,780 --> 00:11:30,100 higher energy level put it in the Sigma star Sigma 1s star that means we have to 426 00:11:30,100 --> 00:11:30,110 star Sigma 1s star that means we have to 427 00:11:30,110 --> 00:11:32,290 star Sigma 1s star that means we have to give to the system that much energy and 428 00:11:32,290 --> 00:11:32,300 give to the system that much energy and 429 00:11:32,300 --> 00:11:34,810 give to the system that much energy and again the second electron that much 430 00:11:34,810 --> 00:11:34,820 again the second electron that much 431 00:11:34,820 --> 00:11:38,020 again the second electron that much energy what that simply means if the 432 00:11:38,020 --> 00:11:38,030 energy what that simply means if the 433 00:11:38,030 --> 00:11:40,330 energy what that simply means if the energy of stabilizations of the bonding 434 00:11:40,330 --> 00:11:40,340 energy of stabilizations of the bonding 435 00:11:40,340 --> 00:11:42,580 energy of stabilizations of the bonding molecular orbital is the same as the 436 00:11:42,580 --> 00:11:42,590 molecular orbital is the same as the 437 00:11:42,590 --> 00:11:44,710 molecular orbital is the same as the energy of destabilization that means of 438 00:11:44,710 --> 00:11:44,720 energy of destabilization that means of 439 00:11:44,720 --> 00:11:47,800 energy of destabilization that means of anti-bonding what i trying to say here 440 00:11:47,800 --> 00:11:47,810 anti-bonding what i trying to say here 441 00:11:47,810 --> 00:11:50,680 anti-bonding what i trying to say here is this that means that this energy this 442 00:11:50,680 --> 00:11:50,690 is this that means that this energy this 443 00:11:50,690 --> 00:11:52,830 is this that means that this energy this distance here is equal to that distance 444 00:11:52,830 --> 00:11:52,840 distance here is equal to that distance 445 00:11:52,840 --> 00:11:57,400 distance here is equal to that distance there will be no energy gain when you 446 00:11:57,400 --> 00:11:57,410 there will be no energy gain when you 447 00:11:57,410 --> 00:12:01,630 there will be no energy gain when you form a helium molecule by combining two 448 00:12:01,630 --> 00:12:01,640 form a helium molecule by combining two 449 00:12:01,640 --> 00:12:05,580 form a helium molecule by combining two helium atoms no energy gain right 450 00:12:05,580 --> 00:12:05,590 helium atoms no energy gain right 451 00:12:05,590 --> 00:12:08,800 helium atoms no energy gain right because when you put the two electrons 452 00:12:08,800 --> 00:12:08,810 because when you put the two electrons 453 00:12:08,810 --> 00:12:10,630 because when you put the two electrons in bonding molecular orbitals the energy 454 00:12:10,630 --> 00:12:10,640 in bonding molecular orbitals the energy 455 00:12:10,640 --> 00:12:12,610 in bonding molecular orbitals the energy will be released but when you have to 456 00:12:12,610 --> 00:12:12,620 will be released but when you have to 457 00:12:12,620 --> 00:12:14,260 will be released but when you have to put the two electrons in anti-bonding 458 00:12:14,260 --> 00:12:14,270 put the two electrons in anti-bonding 459 00:12:14,270 --> 00:12:17,290 put the two electrons in anti-bonding you have to give that much energy to the 460 00:12:17,290 --> 00:12:17,300 you have to give that much energy to the 461 00:12:17,300 --> 00:12:19,570 you have to give that much energy to the molecule again there will be no net 462 00:12:19,570 --> 00:12:19,580 molecule again there will be no net 463 00:12:19,580 --> 00:12:23,080 molecule again there will be no net energy gain actually if you calculate 464 00:12:23,080 --> 00:12:23,090 energy gain actually if you calculate 465 00:12:23,090 --> 00:12:27,700 energy gain actually if you calculate the bond order for helium molecule it 466 00:12:27,700 --> 00:12:27,710 the bond order for helium molecule it 467 00:12:27,710 --> 00:12:30,100 the bond order for helium molecule it will turn out to be like two electrons 468 00:12:30,100 --> 00:12:30,110 will turn out to be like two electrons 469 00:12:30,110 --> 00:12:33,370 will turn out to be like two electrons in bonding molecular orbitals minus two 470 00:12:33,370 --> 00:12:33,380 in bonding molecular orbitals minus two 471 00:12:33,380 --> 00:12:35,620 in bonding molecular orbitals minus two electrons in anti-bonding divided by two 472 00:12:35,620 --> 00:12:35,630 electrons in anti-bonding divided by two 473 00:12:35,630 --> 00:12:38,350 electrons in anti-bonding divided by two equals to zero what does that means that 474 00:12:38,350 --> 00:12:38,360 equals to zero what does that means that 475 00:12:38,360 --> 00:12:42,490 equals to zero what does that means that the bond order in helium molecule turns 476 00:12:42,490 --> 00:12:42,500 the bond order in helium molecule turns 477 00:12:42,500 --> 00:12:45,160 the bond order in helium molecule turns out to be zero that will be interpreted 478 00:12:45,160 --> 00:12:45,170 out to be zero that will be interpreted 479 00:12:45,170 --> 00:12:47,440 out to be zero that will be interpreted in molecular orbital theory that there's 480 00:12:47,440 --> 00:12:47,450 in molecular orbital theory that there's 481 00:12:47,450 --> 00:12:51,040 in molecular orbital theory that there's no energetic reason for those two helium 482 00:12:51,040 --> 00:12:51,050 no energetic reason for those two helium 483 00:12:51,050 --> 00:12:54,460 no energetic reason for those two helium atom to form a molecule right actually 484 00:12:54,460 --> 00:12:54,470 atom to form a molecule right actually 485 00:12:54,470 --> 00:12:58,000 atom to form a molecule right actually in reality we know that helium molecule 486 00:12:58,000 --> 00:12:58,010 in reality we know that helium molecule 487 00:12:58,010 --> 00:13:02,770 in reality we know that helium molecule do not exist no helium molecule but the 488 00:13:02,770 --> 00:13:02,780 do not exist no helium molecule but the 489 00:13:02,780 --> 00:13:05,890 do not exist no helium molecule but the hydrogen molecule do exist actually so 490 00:13:05,890 --> 00:13:05,900 hydrogen molecule do exist actually so 491 00:13:05,900 --> 00:13:08,830 hydrogen molecule do exist actually so you see again how the molecular orbital 492 00:13:08,830 --> 00:13:08,840 you see again how the molecular orbital 493 00:13:08,840 --> 00:13:13,450 you see again how the molecular orbital explains that the helium molecule and 494 00:13:13,450 --> 00:13:13,460 explains that the helium molecule and 495 00:13:13,460 --> 00:13:15,640 explains that the helium molecule and the other molecule some neon molecules 496 00:13:15,640 --> 00:13:15,650 the other molecule some neon molecules 497 00:13:15,650 --> 00:13:18,310 the other molecule some neon molecules are band molecules will not exist 498 00:13:18,310 --> 00:13:18,320 are band molecules will not exist 499 00:13:18,320 --> 00:13:20,950 are band molecules will not exist because energetically there will be no 500 00:13:20,950 --> 00:13:20,960 because energetically there will be no 501 00:13:20,960 --> 00:13:24,190 because energetically there will be no gain or the other way to express that 502 00:13:24,190 --> 00:13:24,200 gain or the other way to express that 503 00:13:24,200 --> 00:13:27,910 gain or the other way to express that the bond order becomes zero when bond 504 00:13:27,910 --> 00:13:27,920 the bond order becomes zero when bond 505 00:13:27,920 --> 00:13:29,030 the bond order becomes zero when bond order becomes zero 506 00:13:29,030 --> 00:13:29,040 order becomes zero 507 00:13:29,040 --> 00:13:30,439 order becomes zero that means there's no reason they have 508 00:13:30,439 --> 00:13:30,449 that means there's no reason they have 509 00:13:30,449 --> 00:13:37,509 that means there's no reason they have to stay together as a matter of fact now 510 00:13:37,509 --> 00:13:37,519 to stay together as a matter of fact now 511 00:13:37,519 --> 00:13:39,920 to stay together as a matter of fact now we have talked about we have shown you 512 00:13:39,920 --> 00:13:39,930 we have talked about we have shown you 513 00:13:39,930 --> 00:13:44,329 we have talked about we have shown you how I've shown you how the 1s orbital 514 00:13:44,329 --> 00:13:44,339 how I've shown you how the 1s orbital 515 00:13:44,339 --> 00:13:48,650 how I've shown you how the 1s orbital will combine to form a bonding molecular 516 00:13:48,650 --> 00:13:48,660 will combine to form a bonding molecular 517 00:13:48,660 --> 00:13:50,509 will combine to form a bonding molecular orbital with the Sigma symmetry and 518 00:13:50,509 --> 00:13:50,519 orbital with the Sigma symmetry and 519 00:13:50,519 --> 00:13:53,180 orbital with the Sigma symmetry and anti-bonding molecular orbital with 520 00:13:53,180 --> 00:13:53,190 anti-bonding molecular orbital with 521 00:13:53,190 --> 00:13:57,170 anti-bonding molecular orbital with again Sigma symmetry star how about the 522 00:13:57,170 --> 00:13:57,180 again Sigma symmetry star how about the 523 00:13:57,180 --> 00:14:01,040 again Sigma symmetry star how about the linear combinations of 2p orbitals to 524 00:14:01,040 --> 00:14:01,050 linear combinations of 2p orbitals to 525 00:14:01,050 --> 00:14:02,480 linear combinations of 2p orbitals to form a molecular orbital 526 00:14:02,480 --> 00:14:02,490 form a molecular orbital 527 00:14:02,490 --> 00:14:08,350 form a molecular orbital now here the examples we can combine the 528 00:14:08,350 --> 00:14:08,360 now here the examples we can combine the 529 00:14:08,360 --> 00:14:10,340 now here the examples we can combine the 2p orbitals 530 00:14:10,340 --> 00:14:10,350 2p orbitals 531 00:14:10,350 --> 00:14:14,210 2p orbitals linearly head-on type that means 532 00:14:14,210 --> 00:14:14,220 linearly head-on type that means 533 00:14:14,220 --> 00:14:16,639 linearly head-on type that means head-to-head fashion and then we will 534 00:14:16,639 --> 00:14:16,649 head-to-head fashion and then we will 535 00:14:16,649 --> 00:14:20,269 head-to-head fashion and then we will simply get two molecular orbitals like 536 00:14:20,269 --> 00:14:20,279 simply get two molecular orbitals like 537 00:14:20,279 --> 00:14:22,939 simply get two molecular orbitals like this this is the bonding molecular 538 00:14:22,939 --> 00:14:22,949 this this is the bonding molecular 539 00:14:22,949 --> 00:14:25,910 this this is the bonding molecular orbitals and which has a sigma symmetry 540 00:14:25,910 --> 00:14:25,920 orbitals and which has a sigma symmetry 541 00:14:25,920 --> 00:14:28,550 orbitals and which has a sigma symmetry again it has the rotational symmetry 542 00:14:28,550 --> 00:14:28,560 again it has the rotational symmetry 543 00:14:28,560 --> 00:14:31,509 again it has the rotational symmetry with respect to the bond axis actually 544 00:14:31,509 --> 00:14:31,519 with respect to the bond axis actually 545 00:14:31,519 --> 00:14:35,180 with respect to the bond axis actually and this is going to be the anti-bonding 546 00:14:35,180 --> 00:14:35,190 and this is going to be the anti-bonding 547 00:14:35,190 --> 00:14:37,850 and this is going to be the anti-bonding molecular orbitals and this is simply 548 00:14:37,850 --> 00:14:37,860 molecular orbitals and this is simply 549 00:14:37,860 --> 00:14:42,110 molecular orbitals and this is simply called Sigma 2p that means the symmetry 550 00:14:42,110 --> 00:14:42,120 called Sigma 2p that means the symmetry 551 00:14:42,120 --> 00:14:44,389 called Sigma 2p that means the symmetry is Sigma and it is obtained by linear 552 00:14:44,389 --> 00:14:44,399 is Sigma and it is obtained by linear 553 00:14:44,399 --> 00:14:46,519 is Sigma and it is obtained by linear combinations of these 2p orbitals and 554 00:14:46,519 --> 00:14:46,529 combinations of these 2p orbitals and 555 00:14:46,529 --> 00:14:48,949 combinations of these 2p orbitals and this is the Sigma star now again you see 556 00:14:48,949 --> 00:14:48,959 this is the Sigma star now again you see 557 00:14:48,959 --> 00:14:54,110 this is the Sigma star now again you see the electron in bonding orbital more 558 00:14:54,110 --> 00:14:54,120 the electron in bonding orbital more 559 00:14:54,120 --> 00:14:56,750 the electron in bonding orbital more concentrates between the nuclei higher 560 00:14:56,750 --> 00:14:56,760 concentrates between the nuclei higher 561 00:14:56,760 --> 00:14:59,120 concentrates between the nuclei higher electron density here but in 562 00:14:59,120 --> 00:14:59,130 electron density here but in 563 00:14:59,130 --> 00:15:01,430 electron density here but in anti-bonding molecular orbital if there 564 00:15:01,430 --> 00:15:01,440 anti-bonding molecular orbital if there 565 00:15:01,440 --> 00:15:03,980 anti-bonding molecular orbital if there is electron there the probability of 566 00:15:03,980 --> 00:15:03,990 is electron there the probability of 567 00:15:03,990 --> 00:15:05,629 is electron there the probability of finding the electron right in the middle 568 00:15:05,629 --> 00:15:05,639 finding the electron right in the middle 569 00:15:05,639 --> 00:15:07,699 finding the electron right in the middle here on this plane is 0 and they are 570 00:15:07,699 --> 00:15:07,709 here on this plane is 0 and they are 571 00:15:07,709 --> 00:15:12,290 here on this plane is 0 and they are more concentrated out here off the inter 572 00:15:12,290 --> 00:15:12,300 more concentrated out here off the inter 573 00:15:12,300 --> 00:15:15,559 more concentrated out here off the inter nuclear volume into nuclear space as a 574 00:15:15,559 --> 00:15:15,569 nuclear volume into nuclear space as a 575 00:15:15,569 --> 00:15:18,019 nuclear volume into nuclear space as a matter of fact so these are again the 576 00:15:18,019 --> 00:15:18,029 matter of fact so these are again the 577 00:15:18,029 --> 00:15:21,050 matter of fact so these are again the sigma bonding and sigma anti-bonding 578 00:15:21,050 --> 00:15:21,060 sigma bonding and sigma anti-bonding 579 00:15:21,060 --> 00:15:23,689 sigma bonding and sigma anti-bonding molecular orbitals which is obtained by 580 00:15:23,689 --> 00:15:23,699 molecular orbitals which is obtained by 581 00:15:23,699 --> 00:15:25,879 molecular orbitals which is obtained by linear combinations of 2p orbitals in 582 00:15:25,879 --> 00:15:25,889 linear combinations of 2p orbitals in 583 00:15:25,889 --> 00:15:29,179 linear combinations of 2p orbitals in head-on fashion now the second example 584 00:15:29,179 --> 00:15:29,189 head-on fashion now the second example 585 00:15:29,189 --> 00:15:33,710 head-on fashion now the second example shows how we simply combine the two 586 00:15:33,710 --> 00:15:33,720 shows how we simply combine the two 587 00:15:33,720 --> 00:15:38,509 shows how we simply combine the two side-by-side simply P orbitals to get a 588 00:15:38,509 --> 00:15:38,519 side-by-side simply P orbitals to get a 589 00:15:38,519 --> 00:15:43,190 side-by-side simply P orbitals to get a molecular orbital and here we have side 590 00:15:43,190 --> 00:15:43,200 molecular orbital and here we have side 591 00:15:43,200 --> 00:15:45,650 molecular orbital and here we have side sort of linear combinations of two P 592 00:15:45,650 --> 00:15:45,660 sort of linear combinations of two P 593 00:15:45,660 --> 00:15:48,980 sort of linear combinations of two P orbitals this is the bonding and this is 594 00:15:48,980 --> 00:15:48,990 orbitals this is the bonding and this is 595 00:15:48,990 --> 00:15:51,639 orbitals this is the bonding and this is the anti-bonding molecular orbital now 596 00:15:51,639 --> 00:15:51,649 the anti-bonding molecular orbital now 597 00:15:51,649 --> 00:15:56,360 the anti-bonding molecular orbital now again remember this these orbitals 598 00:15:56,360 --> 00:15:56,370 again remember this these orbitals 599 00:15:56,370 --> 00:15:57,800 again remember this these orbitals bonding and antibonding molecular 600 00:15:57,800 --> 00:15:57,810 bonding and antibonding molecular 601 00:15:57,810 --> 00:16:01,160 bonding and antibonding molecular orbitals do not have rotational symmetry 602 00:16:01,160 --> 00:16:01,170 orbitals do not have rotational symmetry 603 00:16:01,170 --> 00:16:04,579 orbitals do not have rotational symmetry with respect to the bond axis therefore 604 00:16:04,579 --> 00:16:04,589 with respect to the bond axis therefore 605 00:16:04,589 --> 00:16:09,340 with respect to the bond axis therefore they are PI type and we call them PI 2p 606 00:16:09,340 --> 00:16:09,350 they are PI type and we call them PI 2p 607 00:16:09,350 --> 00:16:12,949 they are PI type and we call them PI 2p bonding and PI 2p star means it is 608 00:16:12,949 --> 00:16:12,959 bonding and PI 2p star means it is 609 00:16:12,959 --> 00:16:16,100 bonding and PI 2p star means it is anti-bonding now you can simply combine 610 00:16:16,100 --> 00:16:16,110 anti-bonding now you can simply combine 611 00:16:16,110 --> 00:16:17,990 anti-bonding now you can simply combine the other 2p orbitals in the same 612 00:16:17,990 --> 00:16:18,000 the other 2p orbitals in the same 613 00:16:18,000 --> 00:16:20,629 the other 2p orbitals in the same fashion like this as a matter of fact 614 00:16:20,629 --> 00:16:20,639 fashion like this as a matter of fact 615 00:16:20,639 --> 00:16:24,139 fashion like this as a matter of fact and this is going to be simply again PI 616 00:16:24,139 --> 00:16:24,149 and this is going to be simply again PI 617 00:16:24,149 --> 00:16:28,519 and this is going to be simply again PI 2p star and PI 2p just look in this 618 00:16:28,519 --> 00:16:28,529 2p star and PI 2p just look in this 619 00:16:28,529 --> 00:16:31,519 2p star and PI 2p just look in this orbitals from the other side right you 620 00:16:31,519 --> 00:16:31,529 orbitals from the other side right you 621 00:16:31,529 --> 00:16:34,939 orbitals from the other side right you just rotated 90 degrees as a matter of 622 00:16:34,939 --> 00:16:34,949 just rotated 90 degrees as a matter of 623 00:16:34,949 --> 00:16:48,880 just rotated 90 degrees as a matter of fact now when you simply examine the 624 00:16:48,880 --> 00:16:48,890 fact now when you simply examine the 625 00:16:48,890 --> 00:16:51,920 fact now when you simply examine the molecular orbitals in homonuclear 626 00:16:51,920 --> 00:16:51,930 molecular orbitals in homonuclear 627 00:16:51,930 --> 00:16:54,650 molecular orbitals in homonuclear diatomic molecules homonuclear diatomic 628 00:16:54,650 --> 00:16:54,660 diatomic molecules homonuclear diatomic 629 00:16:54,660 --> 00:16:59,170 diatomic molecules homonuclear diatomic molecules let's simply take an example 630 00:16:59,170 --> 00:16:59,180 molecules let's simply take an example 631 00:16:59,180 --> 00:17:04,789 molecules let's simply take an example consider the oxygen molecule or let's 632 00:17:04,789 --> 00:17:04,799 consider the oxygen molecule or let's 633 00:17:04,799 --> 00:17:13,250 consider the oxygen molecule or let's say nitrogen molecule like this so in a 634 00:17:13,250 --> 00:17:13,260 say nitrogen molecule like this so in a 635 00:17:13,260 --> 00:17:16,669 say nitrogen molecule like this so in a nitrogen we have electron configuration 636 00:17:16,669 --> 00:17:16,679 nitrogen we have electron configuration 637 00:17:16,679 --> 00:17:22,069 nitrogen we have electron configuration 1 s 2 2 s 2 and T 2 P 3 electrons like 638 00:17:22,069 --> 00:17:22,079 1 s 2 2 s 2 and T 2 P 3 electrons like 639 00:17:22,079 --> 00:17:29,000 1 s 2 2 s 2 and T 2 P 3 electrons like this so if I simply try to write down 640 00:17:29,000 --> 00:17:29,010 this so if I simply try to write down 641 00:17:29,010 --> 00:17:31,580 this so if I simply try to write down the molecular orbital energy level 642 00:17:31,580 --> 00:17:31,590 the molecular orbital energy level 643 00:17:31,590 --> 00:17:35,000 the molecular orbital energy level diagram for this it would be again as 644 00:17:35,000 --> 00:17:35,010 diagram for this it would be again as 645 00:17:35,010 --> 00:17:43,100 diagram for this it would be again as follow the 1s orbital actually of this 646 00:17:43,100 --> 00:17:43,110 follow the 1s orbital actually of this 647 00:17:43,110 --> 00:17:45,740 follow the 1s orbital actually of this hydrogen will combine with the other 1s 648 00:17:45,740 --> 00:17:45,750 hydrogen will combine with the other 1s 649 00:17:45,750 --> 00:17:48,970 hydrogen will combine with the other 1s orbital of the other nitrogen actually 650 00:17:48,970 --> 00:17:48,980 orbital of the other nitrogen actually 651 00:17:48,980 --> 00:17:51,799 orbital of the other nitrogen actually let me just put it over here this is the 652 00:17:51,799 --> 00:17:51,809 let me just put it over here this is the 653 00:17:51,809 --> 00:17:54,880 let me just put it over here this is the energy so let's say this is the 654 00:17:54,880 --> 00:17:54,890 energy so let's say this is the 655 00:17:54,890 --> 00:18:00,370 energy so let's say this is the 1s orbital of the first nitrogen let's 656 00:18:00,370 --> 00:18:00,380 1s orbital of the first nitrogen let's 657 00:18:00,380 --> 00:18:04,360 1s orbital of the first nitrogen let's say nitrogen a or just nitrogen and here 658 00:18:04,360 --> 00:18:04,370 say nitrogen a or just nitrogen and here 659 00:18:04,370 --> 00:18:08,980 say nitrogen a or just nitrogen and here is I have the two s orbitals orbital and 660 00:18:08,980 --> 00:18:08,990 is I have the two s orbitals orbital and 661 00:18:08,990 --> 00:18:14,380 is I have the two s orbitals orbital and here I have two P orbitals they are 662 00:18:14,380 --> 00:18:14,390 here I have two P orbitals they are 663 00:18:14,390 --> 00:18:17,500 here I have two P orbitals they are degenerate right degenerate that means 664 00:18:17,500 --> 00:18:17,510 degenerate right degenerate that means 665 00:18:17,510 --> 00:18:19,660 degenerate right degenerate that means they have the same energies this is the 666 00:18:19,660 --> 00:18:19,670 they have the same energies this is the 667 00:18:19,670 --> 00:18:22,980 they have the same energies this is the energy order so here I have three 668 00:18:22,980 --> 00:18:22,990 energy order so here I have three 669 00:18:22,990 --> 00:18:26,320 energy order so here I have three electrons this is the simply electron 670 00:18:26,320 --> 00:18:26,330 electrons this is the simply electron 671 00:18:26,330 --> 00:18:29,970 electrons this is the simply electron configuration and also the relative 672 00:18:29,970 --> 00:18:29,980 configuration and also the relative 673 00:18:29,980 --> 00:18:33,730 configuration and also the relative energies of these now the other nitrogen 674 00:18:33,730 --> 00:18:33,740 energies of these now the other nitrogen 675 00:18:33,740 --> 00:18:36,910 energies of these now the other nitrogen here again will be the same here one s 676 00:18:36,910 --> 00:18:36,920 here again will be the same here one s 677 00:18:36,920 --> 00:18:41,830 here again will be the same here one s let's call that B two electrons and two 678 00:18:41,830 --> 00:18:41,840 let's call that B two electrons and two 679 00:18:41,840 --> 00:18:44,980 let's call that B two electrons and two s here two electrons same energy because 680 00:18:44,980 --> 00:18:44,990 s here two electrons same energy because 681 00:18:44,990 --> 00:18:47,350 s here two electrons same energy because the same nitrogen atoms and the P 682 00:18:47,350 --> 00:18:47,360 the same nitrogen atoms and the P 683 00:18:47,360 --> 00:18:51,700 the same nitrogen atoms and the P orbitals here like this and these are 684 00:18:51,700 --> 00:18:51,710 orbitals here like this and these are 685 00:18:51,710 --> 00:18:54,090 orbitals here like this and these are the two P orbitals three of those 686 00:18:54,090 --> 00:18:54,100 the two P orbitals three of those 687 00:18:54,100 --> 00:18:56,080 the two P orbitals three of those perpendicular to each other as a matter 688 00:18:56,080 --> 00:18:56,090 perpendicular to each other as a matter 689 00:18:56,090 --> 00:19:02,890 perpendicular to each other as a matter of fact so how are we going to obtain 690 00:19:02,890 --> 00:19:02,900 of fact so how are we going to obtain 691 00:19:02,900 --> 00:19:04,780 of fact so how are we going to obtain the molecular orbital constructive 692 00:19:04,780 --> 00:19:04,790 the molecular orbital constructive 693 00:19:04,790 --> 00:19:06,370 the molecular orbital constructive molecular orbitals by combining the 694 00:19:06,370 --> 00:19:06,380 molecular orbitals by combining the 695 00:19:06,380 --> 00:19:08,350 molecular orbitals by combining the atomic orbitals we can combine these two 696 00:19:08,350 --> 00:19:08,360 atomic orbitals we can combine these two 697 00:19:08,360 --> 00:19:20,370 atomic orbitals we can combine these two and obtain bonding and anti-bonding and 698 00:19:20,370 --> 00:19:20,380 and obtain bonding and anti-bonding and 699 00:19:20,380 --> 00:19:25,480 and obtain bonding and anti-bonding and this is going to be simply Sigma 1 s 700 00:19:25,480 --> 00:19:25,490 this is going to be simply Sigma 1 s 701 00:19:25,490 --> 00:19:30,810 this is going to be simply Sigma 1 s this is going to be Sigma 1 s star and 702 00:19:30,810 --> 00:19:30,820 this is going to be Sigma 1 s star and 703 00:19:30,820 --> 00:19:34,620 this is going to be Sigma 1 s star and now here combining these two I will have 704 00:19:34,620 --> 00:19:34,630 now here combining these two I will have 705 00:19:34,630 --> 00:19:44,200 now here combining these two I will have simply bonding and anti-bonding same 706 00:19:44,200 --> 00:19:44,210 simply bonding and anti-bonding same 707 00:19:44,210 --> 00:19:46,060 simply bonding and anti-bonding same things just the energies are different 708 00:19:46,060 --> 00:19:46,070 things just the energies are different 709 00:19:46,070 --> 00:19:50,290 things just the energies are different and this is going to be Sigma 2 s and 710 00:19:50,290 --> 00:19:50,300 and this is going to be Sigma 2 s and 711 00:19:50,300 --> 00:19:53,800 and this is going to be Sigma 2 s and this is going to be Sigma 2 s star like 712 00:19:53,800 --> 00:19:53,810 this is going to be Sigma 2 s star like 713 00:19:53,810 --> 00:19:58,060 this is going to be Sigma 2 s star like this and then we will have the P 714 00:19:58,060 --> 00:19:58,070 this and then we will have the P 715 00:19:58,070 --> 00:20:03,940 this and then we will have the P orbitals right the P orbitals now 2p 716 00:20:03,940 --> 00:20:03,950 orbitals right the P orbitals now 2p 717 00:20:03,950 --> 00:20:08,560 orbitals right the P orbitals now 2p orbitals head-on will combine to form 718 00:20:08,560 --> 00:20:08,570 orbitals head-on will combine to form 719 00:20:08,570 --> 00:20:24,419 orbitals head-on will combine to form put the little bit higher energy-wise 720 00:20:24,419 --> 00:20:24,429 721 00:20:24,429 --> 00:20:31,940 2p orbitals 722 00:20:31,940 --> 00:20:31,950 723 00:20:31,950 --> 00:20:37,490 so here I will have abundant molecular 724 00:20:37,490 --> 00:20:37,500 so here I will have abundant molecular 725 00:20:37,500 --> 00:20:38,510 so here I will have abundant molecular orbital's 726 00:20:38,510 --> 00:20:38,520 orbital's 727 00:20:38,520 --> 00:20:41,300 orbital's combined in two P orbitals head-on and 728 00:20:41,300 --> 00:20:41,310 combined in two P orbitals head-on and 729 00:20:41,310 --> 00:20:48,530 combined in two P orbitals head-on and so this is going to be Sigma 2p you can 730 00:20:48,530 --> 00:20:48,540 so this is going to be Sigma 2p you can 731 00:20:48,540 --> 00:20:51,260 so this is going to be Sigma 2p you can call that Z for example and now then I 732 00:20:51,260 --> 00:20:51,270 call that Z for example and now then I 733 00:20:51,270 --> 00:20:59,540 call that Z for example and now then I will have here Sigma star 2p z the 734 00:20:59,540 --> 00:20:59,550 will have here Sigma star 2p z the 735 00:20:59,550 --> 00:21:01,160 will have here Sigma star 2p z the anti-bonding molecular orbitals 736 00:21:01,160 --> 00:21:01,170 anti-bonding molecular orbitals 737 00:21:01,170 --> 00:21:06,380 anti-bonding molecular orbitals these are hand on linear combinations to 738 00:21:06,380 --> 00:21:06,390 these are hand on linear combinations to 739 00:21:06,390 --> 00:21:08,750 these are hand on linear combinations to form the Sigma symmetry bonding and 740 00:21:08,750 --> 00:21:08,760 form the Sigma symmetry bonding and 741 00:21:08,760 --> 00:21:11,510 form the Sigma symmetry bonding and anti-bonding molecular orbitals now we 742 00:21:11,510 --> 00:21:11,520 anti-bonding molecular orbitals now we 743 00:21:11,520 --> 00:21:13,940 anti-bonding molecular orbitals now we used one of the P orbitals here right to 744 00:21:13,940 --> 00:21:13,950 used one of the P orbitals here right to 745 00:21:13,950 --> 00:21:15,230 used one of the P orbitals here right to get those one from there 746 00:21:15,230 --> 00:21:15,240 get those one from there 747 00:21:15,240 --> 00:21:18,320 get those one from there there are two more and remember they are 748 00:21:18,320 --> 00:21:18,330 there are two more and remember they are 749 00:21:18,330 --> 00:21:19,940 there are two more and remember they are perpendicular to this that means they 750 00:21:19,940 --> 00:21:19,950 perpendicular to this that means they 751 00:21:19,950 --> 00:21:22,610 perpendicular to this that means they are this over here like this and now 752 00:21:22,610 --> 00:21:22,620 are this over here like this and now 753 00:21:22,620 --> 00:21:27,380 are this over here like this and now they will combine sideways like and then 754 00:21:27,380 --> 00:21:27,390 they will combine sideways like and then 755 00:21:27,390 --> 00:21:30,380 they will combine sideways like and then will we will get bonding molecular 756 00:21:30,380 --> 00:21:30,390 will we will get bonding molecular 757 00:21:30,390 --> 00:21:33,200 will we will get bonding molecular orbitals with the PI symmetry and type 758 00:21:33,200 --> 00:21:33,210 orbitals with the PI symmetry and type 759 00:21:33,210 --> 00:21:34,730 orbitals with the PI symmetry and type on the molecular orbital with the PI 760 00:21:34,730 --> 00:21:34,740 on the molecular orbital with the PI 761 00:21:34,740 --> 00:21:37,820 on the molecular orbital with the PI symmetry so let's simply put it over 762 00:21:37,820 --> 00:21:37,830 symmetry so let's simply put it over 763 00:21:37,830 --> 00:21:44,290 symmetry so let's simply put it over here bonding and anti-bonding like this 764 00:21:44,290 --> 00:21:44,300 here bonding and anti-bonding like this 765 00:21:44,300 --> 00:21:48,350 here bonding and anti-bonding like this but now there are two more P orbitals on 766 00:21:48,350 --> 00:21:48,360 but now there are two more P orbitals on 767 00:21:48,360 --> 00:21:51,830 but now there are two more P orbitals on the nitrogen which are perpendicular to 768 00:21:51,830 --> 00:21:51,840 the nitrogen which are perpendicular to 769 00:21:51,840 --> 00:21:54,020 the nitrogen which are perpendicular to that there these two they will also 770 00:21:54,020 --> 00:21:54,030 that there these two they will also 771 00:21:54,030 --> 00:21:57,410 that there these two they will also combine sideways like this to form 772 00:21:57,410 --> 00:21:57,420 combine sideways like this to form 773 00:21:57,420 --> 00:22:00,890 combine sideways like this to form exactly the same symmetry pi symmetry 774 00:22:00,890 --> 00:22:00,900 exactly the same symmetry pi symmetry 775 00:22:00,900 --> 00:22:02,720 exactly the same symmetry pi symmetry bonding and anti-bonding molecular 776 00:22:02,720 --> 00:22:02,730 bonding and anti-bonding molecular 777 00:22:02,730 --> 00:22:06,400 bonding and anti-bonding molecular orbitals than v just just like these two 778 00:22:06,400 --> 00:22:06,410 orbitals than v just just like these two 779 00:22:06,410 --> 00:22:09,980 orbitals than v just just like these two right so the energies of the bonding 780 00:22:09,980 --> 00:22:09,990 right so the energies of the bonding 781 00:22:09,990 --> 00:22:11,990 right so the energies of the bonding molecular orbitals second one will be 782 00:22:11,990 --> 00:22:12,000 molecular orbitals second one will be 783 00:22:12,000 --> 00:22:15,920 molecular orbitals second one will be same here and then over there like this 784 00:22:15,920 --> 00:22:15,930 same here and then over there like this 785 00:22:15,930 --> 00:22:18,800 same here and then over there like this so I will simply combine I put it like 786 00:22:18,800 --> 00:22:18,810 so I will simply combine I put it like 787 00:22:18,810 --> 00:22:24,350 so I will simply combine I put it like that now I will put the electrons here 788 00:22:24,350 --> 00:22:24,360 that now I will put the electrons here 789 00:22:24,360 --> 00:22:28,850 that now I will put the electrons here and two electrons here three electrons 790 00:22:28,850 --> 00:22:28,860 and two electrons here three electrons 791 00:22:28,860 --> 00:22:31,280 and two electrons here three electrons there two electron here two electrons 792 00:22:31,280 --> 00:22:31,290 there two electron here two electrons 793 00:22:31,290 --> 00:22:36,890 there two electron here two electrons there and then I have simply one 794 00:22:36,890 --> 00:22:36,900 there and then I have simply one 795 00:22:36,900 --> 00:22:41,240 there and then I have simply one electron there and then I will have one 796 00:22:41,240 --> 00:22:41,250 electron there and then I will have one 797 00:22:41,250 --> 00:22:45,170 electron there and then I will have one electron there actually two 798 00:22:45,170 --> 00:22:45,180 electron there actually two 799 00:22:45,180 --> 00:22:57,280 electron there actually two four six eight ten and 800 00:22:57,280 --> 00:22:57,290 801 00:22:57,290 --> 00:23:03,000 okay let's say put here 2 4 6 7 802 00:23:03,000 --> 00:23:03,010 okay let's say put here 2 4 6 7 803 00:23:03,010 --> 00:23:11,380 okay let's say put here 2 4 6 7 electrons 14 8 10 yes and then I have to 804 00:23:11,380 --> 00:23:11,390 electrons 14 8 10 yes and then I have to 805 00:23:11,390 --> 00:23:36,730 electrons 14 8 10 yes and then I have to put one more here like this 806 00:23:36,730 --> 00:23:36,740 807 00:23:36,740 --> 00:23:42,990 it would be simply for and then I have 808 00:23:42,990 --> 00:23:43,000 it would be simply for and then I have 809 00:23:43,000 --> 00:23:51,580 it would be simply for and then I have six there no no I got that over here all 810 00:23:51,580 --> 00:23:51,590 six there no no I got that over here all 811 00:23:51,590 --> 00:23:54,490 six there no no I got that over here all right now I guess I get the correct 812 00:23:54,490 --> 00:23:54,500 right now I guess I get the correct 813 00:23:54,500 --> 00:24:00,520 right now I guess I get the correct electron configurations 2 4 6 8 10 12 14 814 00:24:00,520 --> 00:24:00,530 electron configurations 2 4 6 8 10 12 14 815 00:24:00,530 --> 00:24:03,810 electron configurations 2 4 6 8 10 12 14 total number of electrons I put it there 816 00:24:03,810 --> 00:24:03,820 total number of electrons I put it there 817 00:24:03,820 --> 00:24:05,250 total number of electrons I put it there okay 818 00:24:05,250 --> 00:24:05,260 okay 819 00:24:05,260 --> 00:24:09,580 okay this becomes the energy level diagram 820 00:24:09,580 --> 00:24:09,590 this becomes the energy level diagram 821 00:24:09,590 --> 00:24:12,760 this becomes the energy level diagram for nitrogen molecule let me put it over 822 00:24:12,760 --> 00:24:12,770 for nitrogen molecule let me put it over 823 00:24:12,770 --> 00:24:16,600 for nitrogen molecule let me put it over here this is n 2 molecules according to 824 00:24:16,600 --> 00:24:16,610 here this is n 2 molecules according to 825 00:24:16,610 --> 00:24:19,950 here this is n 2 molecules according to the molecular orbital theory let's 826 00:24:19,950 --> 00:24:19,960 the molecular orbital theory let's 827 00:24:19,960 --> 00:24:26,380 the molecular orbital theory let's simply calculate the bound order and the 828 00:24:26,380 --> 00:24:26,390 simply calculate the bound order and the 829 00:24:26,390 --> 00:24:30,100 simply calculate the bound order and the bond order for this case would be as 830 00:24:30,100 --> 00:24:30,110 bond order for this case would be as 831 00:24:30,110 --> 00:24:32,080 bond order for this case would be as follow the number of electrons in 832 00:24:32,080 --> 00:24:32,090 follow the number of electrons in 833 00:24:32,090 --> 00:24:37,260 follow the number of electrons in bonding molecular orbital two four and 834 00:24:37,260 --> 00:24:37,270 bonding molecular orbital two four and 835 00:24:37,270 --> 00:24:46,480 bonding molecular orbital two four and six eight and ten no two four six eight 836 00:24:46,480 --> 00:24:46,490 six eight and ten no two four six eight 837 00:24:46,490 --> 00:24:52,030 six eight and ten no two four six eight 10 and minus the number of electrons in 838 00:24:52,030 --> 00:24:52,040 10 and minus the number of electrons in 839 00:24:52,040 --> 00:24:54,820 10 and minus the number of electrons in anti-bonding molecular orbitals which 840 00:24:54,820 --> 00:24:54,830 anti-bonding molecular orbitals which 841 00:24:54,830 --> 00:24:55,930 anti-bonding molecular orbitals which are the anti-bonding 842 00:24:55,930 --> 00:24:55,940 are the anti-bonding 843 00:24:55,940 --> 00:24:58,660 are the anti-bonding this is the anti-bonding - this is the 844 00:24:58,660 --> 00:24:58,670 this is the anti-bonding - this is the 845 00:24:58,670 --> 00:25:01,270 this is the anti-bonding - this is the anti-bonding for so let's put that for 846 00:25:01,270 --> 00:25:01,280 anti-bonding for so let's put that for 847 00:25:01,280 --> 00:25:04,799 anti-bonding for so let's put that for there divided by 2 this becomes equal to 848 00:25:04,799 --> 00:25:04,809 there divided by 2 this becomes equal to 849 00:25:04,809 --> 00:25:10,530 there divided by 2 this becomes equal to 3 right so we say that the bond order in 850 00:25:10,530 --> 00:25:10,540 3 right so we say that the bond order in 851 00:25:10,540 --> 00:25:13,570 3 right so we say that the bond order in nitrogen molecule is equal to 3 but 852 00:25:13,570 --> 00:25:13,580 nitrogen molecule is equal to 3 but 853 00:25:13,580 --> 00:25:17,080 nitrogen molecule is equal to 3 but remember it doesn't mean that there are 854 00:25:17,080 --> 00:25:17,090 remember it doesn't mean that there are 855 00:25:17,090 --> 00:25:21,160 remember it doesn't mean that there are triple bond between the nitrogen like in 856 00:25:21,160 --> 00:25:21,170 triple bond between the nitrogen like in 857 00:25:21,170 --> 00:25:25,299 triple bond between the nitrogen like in the valence bond Theory it is just the 858 00:25:25,299 --> 00:25:25,309 the valence bond Theory it is just the 859 00:25:25,309 --> 00:25:29,669 the valence bond Theory it is just the bond order is 3 that's what we say ok 860 00:25:29,669 --> 00:25:29,679 bond order is 3 that's what we say ok 861 00:25:29,679 --> 00:25:36,520 bond order is 3 that's what we say ok now when we simply write the molecular 862 00:25:36,520 --> 00:25:36,530 now when we simply write the molecular 863 00:25:36,530 --> 00:25:39,810 now when we simply write the molecular orbital energy level diagram for 864 00:25:39,810 --> 00:25:39,820 orbital energy level diagram for 865 00:25:39,820 --> 00:25:42,610 orbital energy level diagram for molecules diatomic molecules or other 866 00:25:42,610 --> 00:25:42,620 molecules diatomic molecules or other 867 00:25:42,620 --> 00:25:48,390 molecules diatomic molecules or other molecules we don't consider the core 868 00:25:48,390 --> 00:25:48,400 molecules we don't consider the core 869 00:25:48,400 --> 00:25:50,300 molecules we don't consider the core electron linear 870 00:25:50,300 --> 00:25:50,310 electron linear 871 00:25:50,310 --> 00:25:53,150 electron linear combinations the core electron will 872 00:25:53,150 --> 00:25:53,160 combinations the core electron will 873 00:25:53,160 --> 00:25:55,280 combinations the core electron will simply linearly combine to form 874 00:25:55,280 --> 00:25:55,290 simply linearly combine to form 875 00:25:55,290 --> 00:25:57,680 simply linearly combine to form molecular orbitals and bonding and 876 00:25:57,680 --> 00:25:57,690 molecular orbitals and bonding and 877 00:25:57,690 --> 00:25:59,710 molecular orbitals and bonding and antibonding molecular orbitals but the 878 00:25:59,710 --> 00:25:59,720 antibonding molecular orbitals but the 879 00:25:59,720 --> 00:26:03,710 antibonding molecular orbitals but the interaction of the core electrons will 880 00:26:03,710 --> 00:26:03,720 interaction of the core electrons will 881 00:26:03,720 --> 00:26:07,240 interaction of the core electrons will be very very weakly so when we consider 882 00:26:07,240 --> 00:26:07,250 be very very weakly so when we consider 883 00:26:07,250 --> 00:26:12,980 be very very weakly so when we consider the molecular orbitals in a molecule we 884 00:26:12,980 --> 00:26:12,990 the molecular orbitals in a molecule we 885 00:26:12,990 --> 00:26:17,420 the molecular orbitals in a molecule we only show the molecular orbitals which 886 00:26:17,420 --> 00:26:17,430 only show the molecular orbitals which 887 00:26:17,430 --> 00:26:19,910 only show the molecular orbitals which is obtained by the linear combinations 888 00:26:19,910 --> 00:26:19,920 is obtained by the linear combinations 889 00:26:19,920 --> 00:26:23,270 is obtained by the linear combinations of the valence atomic orbitals valence 890 00:26:23,270 --> 00:26:23,280 of the valence atomic orbitals valence 891 00:26:23,280 --> 00:26:28,010 of the valence atomic orbitals valence orbitals so simply these here is the 892 00:26:28,010 --> 00:26:28,020 orbitals so simply these here is the 893 00:26:28,020 --> 00:26:31,730 orbitals so simply these here is the core electron core orbitals for the 894 00:26:31,730 --> 00:26:31,740 core electron core orbitals for the 895 00:26:31,740 --> 00:26:33,530 core electron core orbitals for the nitrogen atoms so we don't really 896 00:26:33,530 --> 00:26:33,540 nitrogen atoms so we don't really 897 00:26:33,540 --> 00:26:35,900 nitrogen atoms so we don't really consider that because this interactions 898 00:26:35,900 --> 00:26:35,910 consider that because this interactions 899 00:26:35,910 --> 00:26:38,870 consider that because this interactions is very very weak interactions and these 900 00:26:38,870 --> 00:26:38,880 is very very weak interactions and these 901 00:26:38,880 --> 00:26:41,480 is very very weak interactions and these are the valence simply electrons and 902 00:26:41,480 --> 00:26:41,490 are the valence simply electrons and 903 00:26:41,490 --> 00:26:46,160 are the valence simply electrons and these are stronger interactions so this 904 00:26:46,160 --> 00:26:46,170 these are stronger interactions so this 905 00:26:46,170 --> 00:26:48,770 these are stronger interactions so this is 2p set this will be again let's put a 906 00:26:48,770 --> 00:26:48,780 is 2p set this will be again let's put a 907 00:26:48,780 --> 00:26:54,460 is 2p set this will be again let's put a PI 2p and this is going to be pi star 908 00:26:54,460 --> 00:26:54,470 PI 2p and this is going to be pi star 909 00:26:54,470 --> 00:26:58,240 PI 2p and this is going to be pi star 2py orbital and in this case I have PX & 910 00:26:58,240 --> 00:26:58,250 2py orbital and in this case I have PX & 911 00:26:58,250 --> 00:27:03,740 2py orbital and in this case I have PX & 2 py and let's call that px and 2 py 3 P 912 00:27:03,740 --> 00:27:03,750 2 py and let's call that px and 2 py 3 P 913 00:27:03,750 --> 00:27:07,100 2 py and let's call that px and 2 py 3 P orbitals actually combine to form 6 914 00:27:07,100 --> 00:27:07,110 orbitals actually combine to form 6 915 00:27:07,110 --> 00:27:09,140 orbitals actually combine to form 6 molecular orbitals as a matter of fact 916 00:27:09,140 --> 00:27:09,150 molecular orbitals as a matter of fact 917 00:27:09,150 --> 00:27:13,790 molecular orbitals as a matter of fact three bonding 3 anti bonding now this is 918 00:27:13,790 --> 00:27:13,800 three bonding 3 anti bonding now this is 919 00:27:13,800 --> 00:27:18,140 three bonding 3 anti bonding now this is what it simply here this energy level 920 00:27:18,140 --> 00:27:18,150 what it simply here this energy level 921 00:27:18,150 --> 00:27:21,500 what it simply here this energy level diagram just the same as this right we 922 00:27:21,500 --> 00:27:21,510 diagram just the same as this right we 923 00:27:21,510 --> 00:27:26,720 diagram just the same as this right we have the Sigma 2's bonding Sigma star 2 924 00:27:26,720 --> 00:27:26,730 have the Sigma 2's bonding Sigma star 2 925 00:27:26,730 --> 00:27:31,270 have the Sigma 2's bonding Sigma star 2 as anti-bonding and then we have the 926 00:27:31,270 --> 00:27:31,280 as anti-bonding and then we have the 927 00:27:31,280 --> 00:27:36,110 as anti-bonding and then we have the Sigma 2p you could call that - pizzette 928 00:27:36,110 --> 00:27:36,120 Sigma 2p you could call that - pizzette 929 00:27:36,120 --> 00:27:38,300 Sigma 2p you could call that - pizzette actually if you call the inter nuclear 930 00:27:38,300 --> 00:27:38,310 actually if you call the inter nuclear 931 00:27:38,310 --> 00:27:42,110 actually if you call the inter nuclear axis as z-axis and then we have the PI 932 00:27:42,110 --> 00:27:42,120 axis as z-axis and then we have the PI 933 00:27:42,120 --> 00:27:44,990 axis as z-axis and then we have the PI 2p bonding molecular orbiters two of 934 00:27:44,990 --> 00:27:45,000 2p bonding molecular orbiters two of 935 00:27:45,000 --> 00:27:47,450 2p bonding molecular orbiters two of those I indicated them by dashes here 936 00:27:47,450 --> 00:27:47,460 those I indicated them by dashes here 937 00:27:47,460 --> 00:27:50,540 those I indicated them by dashes here like 2 - represents two molecular 938 00:27:50,540 --> 00:27:50,550 like 2 - represents two molecular 939 00:27:50,550 --> 00:27:53,530 like 2 - represents two molecular orbitals and anti bonding and 940 00:27:53,530 --> 00:27:53,540 orbitals and anti bonding and 941 00:27:53,540 --> 00:27:56,780 orbitals and anti bonding and anti-bonding sigma anti-bonding PI 942 00:27:56,780 --> 00:27:56,790 anti-bonding sigma anti-bonding PI 943 00:27:56,790 --> 00:27:59,900 anti-bonding sigma anti-bonding PI orbitals here so we can actually use 944 00:27:59,900 --> 00:27:59,910 orbitals here so we can actually use 945 00:27:59,910 --> 00:28:03,460 orbitals here so we can actually use this diagram to 946 00:28:03,460 --> 00:28:03,470 this diagram to 947 00:28:03,470 --> 00:28:10,000 this diagram to find out to calculate the bond order of 948 00:28:10,000 --> 00:28:10,010 find out to calculate the bond order of 949 00:28:10,010 --> 00:28:15,310 find out to calculate the bond order of all second row diatomic molecules what 950 00:28:15,310 --> 00:28:15,320 all second row diatomic molecules what 951 00:28:15,320 --> 00:28:18,250 all second row diatomic molecules what are they for example let's consider the 952 00:28:18,250 --> 00:28:18,260 are they for example let's consider the 953 00:28:18,260 --> 00:28:23,710 are they for example let's consider the o2 molecule right co2 molecule in o 2 954 00:28:23,710 --> 00:28:23,720 o2 molecule right co2 molecule in o 2 955 00:28:23,720 --> 00:28:27,190 o2 molecule right co2 molecule in o 2 molecule we have the same electron 956 00:28:27,190 --> 00:28:27,200 molecule we have the same electron 957 00:28:27,200 --> 00:28:29,710 molecule we have the same electron configuration here except we have one 958 00:28:29,710 --> 00:28:29,720 configuration here except we have one 959 00:28:29,720 --> 00:28:32,289 configuration here except we have one more electron right in a P orbitals 960 00:28:32,289 --> 00:28:32,299 more electron right in a P orbitals 961 00:28:32,299 --> 00:28:36,190 more electron right in a P orbitals there so that means instead of having 14 962 00:28:36,190 --> 00:28:36,200 there so that means instead of having 14 963 00:28:36,200 --> 00:28:40,120 there so that means instead of having 14 electrons we will have 16 electrons 964 00:28:40,120 --> 00:28:40,130 electrons we will have 16 electrons 965 00:28:40,130 --> 00:28:42,970 electrons we will have 16 electrons right we will have 16 electrons so what 966 00:28:42,970 --> 00:28:42,980 right we will have 16 electrons so what 967 00:28:42,980 --> 00:28:45,190 right we will have 16 electrons so what does that means if I just simply said 968 00:28:45,190 --> 00:28:45,200 does that means if I just simply said 969 00:28:45,200 --> 00:28:51,730 does that means if I just simply said change this to night oxygen here this is 970 00:28:51,730 --> 00:28:51,740 change this to night oxygen here this is 971 00:28:51,740 --> 00:28:53,740 change this to night oxygen here this is the oxygen atom this is the old true 972 00:28:53,740 --> 00:28:53,750 the oxygen atom this is the old true 973 00:28:53,750 --> 00:28:56,080 the oxygen atom this is the old true molecule this is the other oxygen atom 974 00:28:56,080 --> 00:28:56,090 molecule this is the other oxygen atom 975 00:28:56,090 --> 00:28:58,200 molecule this is the other oxygen atom then that means in addition to this 976 00:28:58,200 --> 00:28:58,210 then that means in addition to this 977 00:28:58,210 --> 00:29:00,520 then that means in addition to this actually the energies will be different 978 00:29:00,520 --> 00:29:00,530 actually the energies will be different 979 00:29:00,530 --> 00:29:04,000 actually the energies will be different definitely right I will have simply two 980 00:29:04,000 --> 00:29:04,010 definitely right I will have simply two 981 00:29:04,010 --> 00:29:05,919 definitely right I will have simply two more electrons and those two electrons 982 00:29:05,919 --> 00:29:05,929 more electrons and those two electrons 983 00:29:05,929 --> 00:29:09,669 more electrons and those two electrons will go where they will go to the pi 984 00:29:09,669 --> 00:29:09,679 will go where they will go to the pi 985 00:29:09,679 --> 00:29:12,820 will go where they will go to the pi star 2py orbital right because these are 986 00:29:12,820 --> 00:29:12,830 star 2py orbital right because these are 987 00:29:12,830 --> 00:29:17,620 star 2py orbital right because these are all full so now remember just like in 988 00:29:17,620 --> 00:29:17,630 all full so now remember just like in 989 00:29:17,630 --> 00:29:20,049 all full so now remember just like in the atoms when we put two electrons we 990 00:29:20,049 --> 00:29:20,059 the atoms when we put two electrons we 991 00:29:20,059 --> 00:29:22,180 the atoms when we put two electrons we have to put them both in the same spin 992 00:29:22,180 --> 00:29:22,190 have to put them both in the same spin 993 00:29:22,190 --> 00:29:24,330 have to put them both in the same spin side and put one electron in each 994 00:29:24,330 --> 00:29:24,340 side and put one electron in each 995 00:29:24,340 --> 00:29:26,919 side and put one electron in each orbital and the same thing applies here 996 00:29:26,919 --> 00:29:26,929 orbital and the same thing applies here 997 00:29:26,929 --> 00:29:29,470 orbital and the same thing applies here so I will put one electron there and one 998 00:29:29,470 --> 00:29:29,480 so I will put one electron there and one 999 00:29:29,480 --> 00:29:33,159 so I will put one electron there and one electron there so this is going to be 1000 00:29:33,159 --> 00:29:33,169 electron there so this is going to be 1001 00:29:33,169 --> 00:29:39,789 electron there so this is going to be actually the molecular orbital energy 1002 00:29:39,789 --> 00:29:39,799 actually the molecular orbital energy 1003 00:29:39,799 --> 00:29:44,830 actually the molecular orbital energy level diagram for oxygen molecule right 1004 00:29:44,830 --> 00:29:44,840 level diagram for oxygen molecule right 1005 00:29:44,840 --> 00:29:52,919 level diagram for oxygen molecule right for oxygen molecule yes 1006 00:29:52,919 --> 00:29:52,929 1007 00:29:52,929 --> 00:29:55,440 we are over here 1008 00:29:55,440 --> 00:29:55,450 we are over here 1009 00:29:55,450 --> 00:29:59,470 we are over here no again why we put those here because 1010 00:29:59,470 --> 00:29:59,480 no again why we put those here because 1011 00:29:59,480 --> 00:30:03,610 no again why we put those here because remember just same as in Adam we feel 1012 00:30:03,610 --> 00:30:03,620 remember just same as in Adam we feel 1013 00:30:03,620 --> 00:30:06,310 remember just same as in Adam we feel the atomic orbitals starting from the 1014 00:30:06,310 --> 00:30:06,320 the atomic orbitals starting from the 1015 00:30:06,320 --> 00:30:09,220 the atomic orbitals starting from the lowest and we go to upper higher 1016 00:30:09,220 --> 00:30:09,230 lowest and we go to upper higher 1017 00:30:09,230 --> 00:30:13,380 lowest and we go to upper higher energies right so we can't feel the 1018 00:30:13,380 --> 00:30:13,390 energies right so we can't feel the 1019 00:30:13,390 --> 00:30:16,630 energies right so we can't feel the orbital upper orbital energy wise before 1020 00:30:16,630 --> 00:30:16,640 orbital upper orbital energy wise before 1021 00:30:16,640 --> 00:30:19,090 orbital upper orbital energy wise before we feel the if there isn't 1022 00:30:19,090 --> 00:30:19,100 we feel the if there isn't 1023 00:30:19,100 --> 00:30:22,600 we feel the if there isn't if the orbitals below energy wise is not 1024 00:30:22,600 --> 00:30:22,610 if the orbitals below energy wise is not 1025 00:30:22,610 --> 00:30:25,240 if the orbitals below energy wise is not full so this is not full just we just 1026 00:30:25,240 --> 00:30:25,250 full so this is not full just we just 1027 00:30:25,250 --> 00:30:28,270 full so this is not full just we just put those two electrons there there's a 1028 00:30:28,270 --> 00:30:28,280 put those two electrons there there's a 1029 00:30:28,280 --> 00:30:32,590 put those two electrons there there's a point now consider the oxygen molecule 1030 00:30:32,590 --> 00:30:32,600 point now consider the oxygen molecule 1031 00:30:32,600 --> 00:30:36,820 point now consider the oxygen molecule okay first of all let's try to calculate 1032 00:30:36,820 --> 00:30:36,830 okay first of all let's try to calculate 1033 00:30:36,830 --> 00:30:42,130 okay first of all let's try to calculate the bond order bond order will be for 1034 00:30:42,130 --> 00:30:42,140 the bond order bond order will be for 1035 00:30:42,140 --> 00:30:52,330 the bond order bond order will be for the oxygen again right 2 4 6 10 no eight 1036 00:30:52,330 --> 00:30:52,340 the oxygen again right 2 4 6 10 no eight 1037 00:30:52,340 --> 00:30:58,890 the oxygen again right 2 4 6 10 no eight 10 right this is 10 minus anti-bonding 2 1038 00:30:58,890 --> 00:30:58,900 10 right this is 10 minus anti-bonding 2 1039 00:30:58,900 --> 00:31:05,590 10 right this is 10 minus anti-bonding 2 4 6 6 and then we divided by 2 and this 1040 00:31:05,590 --> 00:31:05,600 4 6 6 and then we divided by 2 and this 1041 00:31:05,600 --> 00:31:08,290 4 6 6 and then we divided by 2 and this becomes 2 so again you see the bond 1042 00:31:08,290 --> 00:31:08,300 becomes 2 so again you see the bond 1043 00:31:08,300 --> 00:31:13,090 becomes 2 so again you see the bond order for oxygen molecule becomes true 1044 00:31:13,090 --> 00:31:13,100 order for oxygen molecule becomes true 1045 00:31:13,100 --> 00:31:17,410 order for oxygen molecule becomes true right now if I simply write down the 1046 00:31:17,410 --> 00:31:17,420 right now if I simply write down the 1047 00:31:17,420 --> 00:31:20,350 right now if I simply write down the lewis structure of nitrogen molecule and 1048 00:31:20,350 --> 00:31:20,360 lewis structure of nitrogen molecule and 1049 00:31:20,360 --> 00:31:21,850 lewis structure of nitrogen molecule and the lewis structure of the oxygen 1050 00:31:21,850 --> 00:31:21,860 the lewis structure of the oxygen 1051 00:31:21,860 --> 00:31:25,810 the lewis structure of the oxygen molecule the nitrogen molecule will 1052 00:31:25,810 --> 00:31:25,820 molecule the nitrogen molecule will 1053 00:31:25,820 --> 00:31:31,990 molecule the nitrogen molecule will simply as follow right this is the 1054 00:31:31,990 --> 00:31:32,000 simply as follow right this is the 1055 00:31:32,000 --> 00:31:33,940 simply as follow right this is the nitrogen molecule we say there is a 1056 00:31:33,940 --> 00:31:33,950 nitrogen molecule we say there is a 1057 00:31:33,950 --> 00:31:38,230 nitrogen molecule we say there is a triple bond between them now the oxygen 1058 00:31:38,230 --> 00:31:38,240 triple bond between them now the oxygen 1059 00:31:38,240 --> 00:31:47,900 triple bond between them now the oxygen molecule is this 1060 00:31:47,900 --> 00:31:47,910 1061 00:31:47,910 --> 00:31:51,300 and we say there's a double bond here 1062 00:31:51,300 --> 00:31:51,310 and we say there's a double bond here 1063 00:31:51,310 --> 00:31:53,370 and we say there's a double bond here like there's that's the total number of 1064 00:31:53,370 --> 00:31:53,380 like there's that's the total number of 1065 00:31:53,380 --> 00:31:58,620 like there's that's the total number of electrons but one thing here let me ask 1066 00:31:58,620 --> 00:31:58,630 electrons but one thing here let me ask 1067 00:31:58,630 --> 00:32:02,910 electrons but one thing here let me ask you this by looking at these Lewis 1068 00:32:02,910 --> 00:32:02,920 you this by looking at these Lewis 1069 00:32:02,920 --> 00:32:09,450 you this by looking at these Lewis structure would you think that the 1070 00:32:09,450 --> 00:32:09,460 structure would you think that the 1071 00:32:09,460 --> 00:32:13,350 structure would you think that the oxygen molecule be paramagnetic or 1072 00:32:13,350 --> 00:32:13,360 oxygen molecule be paramagnetic or 1073 00:32:13,360 --> 00:32:25,010 oxygen molecule be paramagnetic or diamagnetic oxygen molecule now remember 1074 00:32:25,010 --> 00:32:25,020 diamagnetic oxygen molecule now remember 1075 00:32:25,020 --> 00:32:27,660 diamagnetic oxygen molecule now remember to be paramagnetic they should be 1076 00:32:27,660 --> 00:32:27,670 to be paramagnetic they should be 1077 00:32:27,670 --> 00:32:31,110 to be paramagnetic they should be unpaired electron right must must be 1078 00:32:31,110 --> 00:32:31,120 unpaired electron right must must be 1079 00:32:31,120 --> 00:32:33,600 unpaired electron right must must be unpaired electron from the Lewis 1080 00:32:33,600 --> 00:32:33,610 unpaired electron from the Lewis 1081 00:32:33,610 --> 00:32:37,710 unpaired electron from the Lewis structures it seems like there's no 1082 00:32:37,710 --> 00:32:37,720 structures it seems like there's no 1083 00:32:37,720 --> 00:32:41,340 structures it seems like there's no unpaired electron right now remember 1084 00:32:41,340 --> 00:32:41,350 unpaired electron right now remember 1085 00:32:41,350 --> 00:32:44,340 unpaired electron right now remember these are in again hybrid orbitals you 1086 00:32:44,340 --> 00:32:44,350 these are in again hybrid orbitals you 1087 00:32:44,350 --> 00:32:46,140 these are in again hybrid orbitals you can look at these as hybrid orbitals 1088 00:32:46,140 --> 00:32:46,150 can look at these as hybrid orbitals 1089 00:32:46,150 --> 00:32:48,180 can look at these as hybrid orbitals three electrons in one orbital so they 1090 00:32:48,180 --> 00:32:48,190 three electrons in one orbital so they 1091 00:32:48,190 --> 00:32:49,920 three electrons in one orbital so they will be paired up and so on that's not 1092 00:32:49,920 --> 00:32:49,930 will be paired up and so on that's not 1093 00:32:49,930 --> 00:32:56,120 will be paired up and so on that's not so actually the valence bond Theory 1094 00:32:56,120 --> 00:32:56,130 so actually the valence bond Theory 1095 00:32:56,130 --> 00:32:58,260 so actually the valence bond Theory according to the valence bond Theory the 1096 00:32:58,260 --> 00:32:58,270 according to the valence bond Theory the 1097 00:32:58,270 --> 00:33:01,940 according to the valence bond Theory the oxygen molecule should be diamagnetic 1098 00:33:01,940 --> 00:33:01,950 oxygen molecule should be diamagnetic 1099 00:33:01,950 --> 00:33:04,830 oxygen molecule should be diamagnetic that means should have no unpaired 1100 00:33:04,830 --> 00:33:04,840 that means should have no unpaired 1101 00:33:04,840 --> 00:33:10,290 that means should have no unpaired electron but the molecular orbital 1102 00:33:10,290 --> 00:33:10,300 electron but the molecular orbital 1103 00:33:10,300 --> 00:33:12,390 electron but the molecular orbital theory says that the oxygen molecule 1104 00:33:12,390 --> 00:33:12,400 theory says that the oxygen molecule 1105 00:33:12,400 --> 00:33:18,900 theory says that the oxygen molecule should be para magnetic Y because I have 1106 00:33:18,900 --> 00:33:18,910 should be para magnetic Y because I have 1107 00:33:18,910 --> 00:33:22,820 should be para magnetic Y because I have two unpaired electron according to 1108 00:33:22,820 --> 00:33:22,830 two unpaired electron according to 1109 00:33:22,830 --> 00:33:27,180 two unpaired electron according to molecular orbital theory right now 1110 00:33:27,180 --> 00:33:27,190 molecular orbital theory right now 1111 00:33:27,190 --> 00:33:29,400 molecular orbital theory right now according to the molecular orbital 1112 00:33:29,400 --> 00:33:29,410 according to the molecular orbital 1113 00:33:29,410 --> 00:33:31,470 according to the molecular orbital Theory if you consider the nitrogen the 1114 00:33:31,470 --> 00:33:31,480 Theory if you consider the nitrogen the 1115 00:33:31,480 --> 00:33:33,360 Theory if you consider the nitrogen the Lewis structure actually from the Lewis 1116 00:33:33,360 --> 00:33:33,370 Lewis structure actually from the Lewis 1117 00:33:33,370 --> 00:33:34,650 Lewis structure actually from the Lewis structure you can say that it will be 1118 00:33:34,650 --> 00:33:34,660 structure you can say that it will be 1119 00:33:34,660 --> 00:33:38,310 structure you can say that it will be diamagnetic nor electron and also with 1120 00:33:38,310 --> 00:33:38,320 diamagnetic nor electron and also with 1121 00:33:38,320 --> 00:33:40,710 diamagnetic nor electron and also with the molecular orbital Theory remember 1122 00:33:40,710 --> 00:33:40,720 the molecular orbital Theory remember 1123 00:33:40,720 --> 00:33:43,260 the molecular orbital Theory remember nitrogen molecule we have up to here all 1124 00:33:43,260 --> 00:33:43,270 nitrogen molecule we have up to here all 1125 00:33:43,270 --> 00:33:45,750 nitrogen molecule we have up to here all electrons are paired so it should also 1126 00:33:45,750 --> 00:33:45,760 electrons are paired so it should also 1127 00:33:45,760 --> 00:33:50,010 electrons are paired so it should also be diamagnetic no unpaired electron but 1128 00:33:50,010 --> 00:33:50,020 be diamagnetic no unpaired electron but 1129 00:33:50,020 --> 00:33:54,800 be diamagnetic no unpaired electron but for the oxygen it has to be paramagnetic 1130 00:33:54,800 --> 00:33:54,810 1131 00:33:54,810 --> 00:33:58,150 is it paramagnetic yes 1132 00:33:58,150 --> 00:33:58,160 is it paramagnetic yes 1133 00:33:58,160 --> 00:34:02,270 is it paramagnetic yes the oxygen molecule is paramagnetic in 1134 00:34:02,270 --> 00:34:02,280 the oxygen molecule is paramagnetic in 1135 00:34:02,280 --> 00:34:05,510 the oxygen molecule is paramagnetic in fact the explanations of the para 1136 00:34:05,510 --> 00:34:05,520 fact the explanations of the para 1137 00:34:05,520 --> 00:34:07,520 fact the explanations of the para magnetism of oxygen atom is only 1138 00:34:07,520 --> 00:34:07,530 magnetism of oxygen atom is only 1139 00:34:07,530 --> 00:34:11,050 magnetism of oxygen atom is only possible with the molecular orbital 1140 00:34:11,050 --> 00:34:11,060 possible with the molecular orbital 1141 00:34:11,060 --> 00:34:14,750 possible with the molecular orbital theory right just like here molecular 1142 00:34:14,750 --> 00:34:14,760 theory right just like here molecular 1143 00:34:14,760 --> 00:34:16,369 theory right just like here molecular ology Theory actually before the 1144 00:34:16,369 --> 00:34:16,379 ology Theory actually before the 1145 00:34:16,379 --> 00:34:18,080 ology Theory actually before the molecular orbital Theory people thought 1146 00:34:18,080 --> 00:34:18,090 molecular orbital Theory people thought 1147 00:34:18,090 --> 00:34:21,110 molecular orbital Theory people thought that the actually the oxygen molecular 1148 00:34:21,110 --> 00:34:21,120 that the actually the oxygen molecular 1149 00:34:21,120 --> 00:34:23,590 that the actually the oxygen molecular oxygen will be diamagnetic but it is 1150 00:34:23,590 --> 00:34:23,600 oxygen will be diamagnetic but it is 1151 00:34:23,600 --> 00:34:26,060 oxygen will be diamagnetic but it is magnetic it has been measured and it is 1152 00:34:26,060 --> 00:34:26,070 magnetic it has been measured and it is 1153 00:34:26,070 --> 00:34:28,850 magnetic it has been measured and it is part of that there is unpaired electrons 1154 00:34:28,850 --> 00:34:28,860 part of that there is unpaired electrons 1155 00:34:28,860 --> 00:34:35,200 part of that there is unpaired electrons okay now let's see 1156 00:34:35,200 --> 00:34:35,210 1157 00:34:35,210 --> 00:34:47,020 consider this let's let's see n 2 plus 1158 00:34:47,020 --> 00:34:47,030 consider this let's let's see n 2 plus 1159 00:34:47,030 --> 00:34:58,030 consider this let's let's see n 2 plus cation and n 2 minus ni and n 2 here 1160 00:34:58,030 --> 00:34:58,040 cation and n 2 minus ni and n 2 here 1161 00:34:58,040 --> 00:35:04,010 cation and n 2 minus ni and n 2 here neutral ni now let's see let's say this 1162 00:35:04,010 --> 00:35:04,020 neutral ni now let's see let's say this 1163 00:35:04,020 --> 00:35:09,860 neutral ni now let's see let's say this is Plus this is into minus let's 1164 00:35:09,860 --> 00:35:09,870 is Plus this is into minus let's 1165 00:35:09,870 --> 00:35:15,740 is Plus this is into minus let's calculate the bond order for the n 2 and 1166 00:35:15,740 --> 00:35:15,750 calculate the bond order for the n 2 and 1167 00:35:15,750 --> 00:35:18,320 calculate the bond order for the n 2 and 2 plus that means one electron is 1168 00:35:18,320 --> 00:35:18,330 2 plus that means one electron is 1169 00:35:18,330 --> 00:35:22,220 2 plus that means one electron is removed and also n 2 minus that means 1170 00:35:22,220 --> 00:35:22,230 removed and also n 2 minus that means 1171 00:35:22,230 --> 00:35:27,080 removed and also n 2 minus that means one electron is added right so let's say 1172 00:35:27,080 --> 00:35:27,090 one electron is added right so let's say 1173 00:35:27,090 --> 00:35:29,470 one electron is added right so let's say calculate this is we have find it to 1174 00:35:29,470 --> 00:35:29,480 calculate this is we have find it to 1175 00:35:29,480 --> 00:35:34,190 calculate this is we have find it to right now in this case this n 2 plus 1176 00:35:34,190 --> 00:35:34,200 right now in this case this n 2 plus 1177 00:35:34,200 --> 00:35:37,520 right now in this case this n 2 plus means that one electron will be removed 1178 00:35:37,520 --> 00:35:37,530 means that one electron will be removed 1179 00:35:37,530 --> 00:35:41,120 means that one electron will be removed from the upper orbital there actually 1180 00:35:41,120 --> 00:35:41,130 from the upper orbital there actually 1181 00:35:41,130 --> 00:35:42,590 from the upper orbital there actually right 1182 00:35:42,590 --> 00:35:42,600 right 1183 00:35:42,600 --> 00:35:45,260 right that means remember for the nitrogen 1184 00:35:45,260 --> 00:35:45,270 that means remember for the nitrogen 1185 00:35:45,270 --> 00:35:48,230 that means remember for the nitrogen cases we don't have these electrons so 1186 00:35:48,230 --> 00:35:48,240 cases we don't have these electrons so 1187 00:35:48,240 --> 00:35:51,440 cases we don't have these electrons so the highest filled molecular orbital 1188 00:35:51,440 --> 00:35:51,450 the highest filled molecular orbital 1189 00:35:51,450 --> 00:35:53,260 the highest filled molecular orbital which is called the highest occupied 1190 00:35:53,260 --> 00:35:53,270 which is called the highest occupied 1191 00:35:53,270 --> 00:35:56,990 which is called the highest occupied homo we will take one electron from 1192 00:35:56,990 --> 00:35:57,000 homo we will take one electron from 1193 00:35:57,000 --> 00:36:00,950 homo we will take one electron from there to make n2 plus now if I calculate 1194 00:36:00,950 --> 00:36:00,960 there to make n2 plus now if I calculate 1195 00:36:00,960 --> 00:36:04,190 there to make n2 plus now if I calculate the bond order in that case the only 1196 00:36:04,190 --> 00:36:04,200 the bond order in that case the only 1197 00:36:04,200 --> 00:36:07,030 the bond order in that case the only difference will be like here I had 1198 00:36:07,030 --> 00:36:07,040 difference will be like here I had 1199 00:36:07,040 --> 00:36:11,470 difference will be like here I had simply 10 electrons in 1200 00:36:11,470 --> 00:36:11,480 simply 10 electrons in 1201 00:36:11,480 --> 00:36:14,160 simply 10 electrons in in molecular orbitals so now I will have 1202 00:36:14,160 --> 00:36:14,170 in molecular orbitals so now I will have 1203 00:36:14,170 --> 00:36:17,710 in molecular orbitals so now I will have nine electrons in bonding molecular 1204 00:36:17,710 --> 00:36:17,720 nine electrons in bonding molecular 1205 00:36:17,720 --> 00:36:22,330 nine electrons in bonding molecular orbitals so nine minus four will be 1206 00:36:22,330 --> 00:36:22,340 orbitals so nine minus four will be 1207 00:36:22,340 --> 00:36:25,900 orbitals so nine minus four will be simply 5/2 the bond order for this case 1208 00:36:25,900 --> 00:36:25,910 simply 5/2 the bond order for this case 1209 00:36:25,910 --> 00:36:31,450 simply 5/2 the bond order for this case will be two point plus you see again we 1210 00:36:31,450 --> 00:36:31,460 will be two point plus you see again we 1211 00:36:31,460 --> 00:36:33,910 will be two point plus you see again we have fractions of bond order two points 1212 00:36:33,910 --> 00:36:33,920 have fractions of bond order two points 1213 00:36:33,920 --> 00:36:38,980 have fractions of bond order two points plus now how about in 2 minus cases now 1214 00:36:38,980 --> 00:36:38,990 plus now how about in 2 minus cases now 1215 00:36:38,990 --> 00:36:41,620 plus now how about in 2 minus cases now in to minus cases again everything would 1216 00:36:41,620 --> 00:36:41,630 in to minus cases again everything would 1217 00:36:41,630 --> 00:36:45,460 in to minus cases again everything would be the same here right but now I have 1218 00:36:45,460 --> 00:36:45,470 be the same here right but now I have 1219 00:36:45,470 --> 00:36:49,330 be the same here right but now I have one more electrons simply where I will 1220 00:36:49,330 --> 00:36:49,340 one more electrons simply where I will 1221 00:36:49,340 --> 00:36:53,470 one more electrons simply where I will have one more electron over here so that 1222 00:36:53,470 --> 00:36:53,480 have one more electron over here so that 1223 00:36:53,480 --> 00:36:56,650 have one more electron over here so that means that instead of five I will have 1224 00:36:56,650 --> 00:36:56,660 means that instead of five I will have 1225 00:36:56,660 --> 00:36:59,109 means that instead of five I will have six five instead of four I will have 1226 00:36:59,109 --> 00:36:59,119 six five instead of four I will have 1227 00:36:59,119 --> 00:37:03,190 six five instead of four I will have five electrons there and the bond order 1228 00:37:03,190 --> 00:37:03,200 five electrons there and the bond order 1229 00:37:03,200 --> 00:37:06,940 five electrons there and the bond order will be what 10 minus 5 divided by 2 1230 00:37:06,940 --> 00:37:06,950 will be what 10 minus 5 divided by 2 1231 00:37:06,950 --> 00:37:18,340 will be what 10 minus 5 divided by 2 again 2.5 now let's consider the all 2 1232 00:37:18,340 --> 00:37:18,350 again 2.5 now let's consider the all 2 1233 00:37:18,350 --> 00:37:24,910 again 2.5 now let's consider the all 2 molecule and let's see-oh - again all 2 1234 00:37:24,910 --> 00:37:24,920 molecule and let's see-oh - again all 2 1235 00:37:24,920 --> 00:37:31,870 molecule and let's see-oh - again all 2 plus and all 2 - the bond order will be 1236 00:37:31,870 --> 00:37:31,880 plus and all 2 - the bond order will be 1237 00:37:31,880 --> 00:37:34,900 plus and all 2 - the bond order will be for this one we find it - for this one 1238 00:37:34,900 --> 00:37:34,910 for this one we find it - for this one 1239 00:37:34,910 --> 00:37:37,810 for this one we find it - for this one again we will have what now let's think 1240 00:37:37,810 --> 00:37:37,820 again we will have what now let's think 1241 00:37:37,820 --> 00:37:38,740 again we will have what now let's think about it 1242 00:37:38,740 --> 00:37:38,750 about it 1243 00:37:38,750 --> 00:37:40,870 about it this is for the oxygen neutral oxygen 1244 00:37:40,870 --> 00:37:40,880 this is for the oxygen neutral oxygen 1245 00:37:40,880 --> 00:37:43,720 this is for the oxygen neutral oxygen and that means that we take out that 1246 00:37:43,720 --> 00:37:43,730 and that means that we take out that 1247 00:37:43,730 --> 00:37:46,080 and that means that we take out that electron we have to always take the 1248 00:37:46,080 --> 00:37:46,090 electron we have to always take the 1249 00:37:46,090 --> 00:37:49,930 electron we have to always take the electron from the highest energy full 1250 00:37:49,930 --> 00:37:49,940 electron from the highest energy full 1251 00:37:49,940 --> 00:37:51,970 electron from the highest energy full molecular orbital that was the easiest 1252 00:37:51,970 --> 00:37:51,980 molecular orbital that was the easiest 1253 00:37:51,980 --> 00:37:55,420 molecular orbital that was the easiest actually right and so what will happen 1254 00:37:55,420 --> 00:37:55,430 actually right and so what will happen 1255 00:37:55,430 --> 00:37:58,690 actually right and so what will happen this number will be not 6 but it will be 1256 00:37:58,690 --> 00:37:58,700 this number will be not 6 but it will be 1257 00:37:58,700 --> 00:38:02,790 this number will be not 6 but it will be 5 right so what will be the bond order 1258 00:38:02,790 --> 00:38:02,800 5 right so what will be the bond order 1259 00:38:02,800 --> 00:38:08,250 5 right so what will be the bond order 2.5 right so this is going to be 2.5 1260 00:38:08,250 --> 00:38:08,260 2.5 right so this is going to be 2.5 1261 00:38:08,260 --> 00:38:14,200 2.5 right so this is going to be 2.5 like this now how about oh - - now o2 - 1262 00:38:14,200 --> 00:38:14,210 like this now how about oh - - now o2 - 1263 00:38:14,210 --> 00:38:16,349 like this now how about oh - - now o2 - cases we will put the electron up here 1264 00:38:16,349 --> 00:38:16,359 cases we will put the electron up here 1265 00:38:16,359 --> 00:38:19,780 cases we will put the electron up here that means that the number of electron 1266 00:38:19,780 --> 00:38:19,790 that means that the number of electron 1267 00:38:19,790 --> 00:38:23,740 that means that the number of electron in anti-bonding not will not be 6 but it 1268 00:38:23,740 --> 00:38:23,750 in anti-bonding not will not be 6 but it 1269 00:38:23,750 --> 00:38:24,430 in anti-bonding not will not be 6 but it will be 1270 00:38:24,430 --> 00:38:24,440 will be 1271 00:38:24,440 --> 00:38:30,170 will be seven so 10 minus 7 3 divided by 2 it 1272 00:38:30,170 --> 00:38:30,180 seven so 10 minus 7 3 divided by 2 it 1273 00:38:30,180 --> 00:38:34,730 seven so 10 minus 7 3 divided by 2 it will be 1.5 right so the bond order here 1274 00:38:34,730 --> 00:38:34,740 will be 1.5 right so the bond order here 1275 00:38:34,740 --> 00:38:39,019 will be 1.5 right so the bond order here is 1.5 now what does that means all of 1276 00:38:39,019 --> 00:38:39,029 is 1.5 now what does that means all of 1277 00:38:39,029 --> 00:38:42,890 is 1.5 now what does that means all of these this simply means that if you take 1278 00:38:42,890 --> 00:38:42,900 these this simply means that if you take 1279 00:38:42,900 --> 00:38:46,309 these this simply means that if you take an electron from the nitrogen molecule 1280 00:38:46,309 --> 00:38:46,319 an electron from the nitrogen molecule 1281 00:38:46,319 --> 00:38:49,819 an electron from the nitrogen molecule and form an M 2 plus do you think that 1282 00:38:49,819 --> 00:38:49,829 and form an M 2 plus do you think that 1283 00:38:49,829 --> 00:38:53,450 and form an M 2 plus do you think that the molecule is less stable or more 1284 00:38:53,450 --> 00:38:53,460 the molecule is less stable or more 1285 00:38:53,460 --> 00:38:58,269 the molecule is less stable or more stable than the end - now remember again 1286 00:38:58,269 --> 00:38:58,279 stable than the end - now remember again 1287 00:38:58,279 --> 00:39:02,599 stable than the end - now remember again if we use the bond order as criteria for 1288 00:39:02,599 --> 00:39:02,609 if we use the bond order as criteria for 1289 00:39:02,609 --> 00:39:05,210 if we use the bond order as criteria for stability that means the higher the bond 1290 00:39:05,210 --> 00:39:05,220 stability that means the higher the bond 1291 00:39:05,220 --> 00:39:08,569 stability that means the higher the bond order the more stable the molecule so 1292 00:39:08,569 --> 00:39:08,579 order the more stable the molecule so 1293 00:39:08,579 --> 00:39:12,759 order the more stable the molecule so this simply means that the end 2 plus 1294 00:39:12,759 --> 00:39:12,769 this simply means that the end 2 plus 1295 00:39:12,769 --> 00:39:17,269 this simply means that the end 2 plus cation will be less stable than the end 1296 00:39:17,269 --> 00:39:17,279 cation will be less stable than the end 1297 00:39:17,279 --> 00:39:21,380 cation will be less stable than the end - that means removing an electron will 1298 00:39:21,380 --> 00:39:21,390 - that means removing an electron will 1299 00:39:21,390 --> 00:39:25,730 - that means removing an electron will make the n 2 molecule less stable now 1300 00:39:25,730 --> 00:39:25,740 make the n 2 molecule less stable now 1301 00:39:25,740 --> 00:39:29,599 make the n 2 molecule less stable now how about M 2 - this does the same 1302 00:39:29,599 --> 00:39:29,609 how about M 2 - this does the same 1303 00:39:29,609 --> 00:39:30,170 how about M 2 - this does the same things 1304 00:39:30,170 --> 00:39:30,180 things 1305 00:39:30,180 --> 00:39:32,509 things Edden an electron to the nitrogen 1306 00:39:32,509 --> 00:39:32,519 Edden an electron to the nitrogen 1307 00:39:32,519 --> 00:39:35,569 Edden an electron to the nitrogen molecule will also destabilize it 1308 00:39:35,569 --> 00:39:35,579 molecule will also destabilize it 1309 00:39:35,579 --> 00:39:37,940 molecule will also destabilize it because the bond order if you just take 1310 00:39:37,940 --> 00:39:37,950 because the bond order if you just take 1311 00:39:37,950 --> 00:39:40,339 because the bond order if you just take the bond order as criteria for the 1312 00:39:40,339 --> 00:39:40,349 the bond order as criteria for the 1313 00:39:40,349 --> 00:39:42,200 the bond order as criteria for the overall stability of the molecule so 1314 00:39:42,200 --> 00:39:42,210 overall stability of the molecule so 1315 00:39:42,210 --> 00:39:44,450 overall stability of the molecule so that simply means that it will be again 1316 00:39:44,450 --> 00:39:44,460 that simply means that it will be again 1317 00:39:44,460 --> 00:39:48,440 that simply means that it will be again less stable than the neutral but in this 1318 00:39:48,440 --> 00:39:48,450 less stable than the neutral but in this 1319 00:39:48,450 --> 00:39:51,890 less stable than the neutral but in this case here for the oxygen molecule if you 1320 00:39:51,890 --> 00:39:51,900 case here for the oxygen molecule if you 1321 00:39:51,900 --> 00:39:55,430 case here for the oxygen molecule if you remove an electron the bundt order 1322 00:39:55,430 --> 00:39:55,440 remove an electron the bundt order 1323 00:39:55,440 --> 00:39:58,009 remove an electron the bundt order increases what does that means the 1324 00:39:58,009 --> 00:39:58,019 increases what does that means the 1325 00:39:58,019 --> 00:40:01,190 increases what does that means the overall stability of o2 plus is greater 1326 00:40:01,190 --> 00:40:01,200 overall stability of o2 plus is greater 1327 00:40:01,200 --> 00:40:04,400 overall stability of o2 plus is greater than Oh - now if you add an electron 1328 00:40:04,400 --> 00:40:04,410 than Oh - now if you add an electron 1329 00:40:04,410 --> 00:40:08,450 than Oh - now if you add an electron bond order also decreases that means it 1330 00:40:08,450 --> 00:40:08,460 bond order also decreases that means it 1331 00:40:08,460 --> 00:40:10,579 bond order also decreases that means it becomes actually less stable than 1332 00:40:10,579 --> 00:40:10,589 becomes actually less stable than 1333 00:40:10,589 --> 00:40:13,789 becomes actually less stable than neutral oxygen molecule the the anion 1334 00:40:13,789 --> 00:40:13,799 neutral oxygen molecule the the anion 1335 00:40:13,799 --> 00:40:17,240 neutral oxygen molecule the the anion here is less stable oxygen molecule and 1336 00:40:17,240 --> 00:40:17,250 here is less stable oxygen molecule and 1337 00:40:17,250 --> 00:40:18,769 here is less stable oxygen molecule and the cation is less stable but in this 1338 00:40:18,769 --> 00:40:18,779 the cation is less stable but in this 1339 00:40:18,779 --> 00:40:21,319 the cation is less stable but in this case it is just the other way around it 1340 00:40:21,319 --> 00:40:21,329 case it is just the other way around it 1341 00:40:21,329 --> 00:40:23,930 case it is just the other way around it as a matter of fact clear so you see how 1342 00:40:23,930 --> 00:40:23,940 as a matter of fact clear so you see how 1343 00:40:23,940 --> 00:40:28,249 as a matter of fact clear so you see how we use the bond order to compare the 1344 00:40:28,249 --> 00:40:28,259 we use the bond order to compare the 1345 00:40:28,259 --> 00:40:31,609 we use the bond order to compare the stabilities and also to find out how 1346 00:40:31,609 --> 00:40:31,619 stabilities and also to find out how 1347 00:40:31,619 --> 00:40:34,940 stabilities and also to find out how edit electron or remove electron changes 1348 00:40:34,940 --> 00:40:34,950 edit electron or remove electron changes 1349 00:40:34,950 --> 00:40:38,150 edit electron or remove electron changes the overall stability by 1350 00:40:38,150 --> 00:40:38,160 the overall stability by 1351 00:40:38,160 --> 00:40:41,690 the overall stability by the bond order of the molecule 1352 00:40:41,690 --> 00:40:41,700 the bond order of the molecule 1353 00:40:41,700 --> 00:40:48,079 the bond order of the molecule okay let's yes this is again another 1354 00:40:48,079 --> 00:40:48,089 okay let's yes this is again another 1355 00:40:48,089 --> 00:40:52,220 okay let's yes this is again another linear combination of an S orbital and 1356 00:40:52,220 --> 00:40:52,230 linear combination of an S orbital and 1357 00:40:52,230 --> 00:40:55,430 linear combination of an S orbital and the p orbital to form a bonding and 1358 00:40:55,430 --> 00:40:55,440 the p orbital to form a bonding and 1359 00:40:55,440 --> 00:40:57,410 the p orbital to form a bonding and anti-bonding molecular orbital as a 1360 00:40:57,410 --> 00:40:57,420 anti-bonding molecular orbital as a 1361 00:40:57,420 --> 00:41:01,339 anti-bonding molecular orbital as a matter of fact and it has a sigma 1362 00:41:01,339 --> 00:41:01,349 matter of fact and it has a sigma 1363 00:41:01,349 --> 00:41:04,339 matter of fact and it has a sigma symmetry like this you can simply 1364 00:41:04,339 --> 00:41:04,349 symmetry like this you can simply 1365 00:41:04,349 --> 00:41:06,620 symmetry like this you can simply combine that and bonding and bond 1366 00:41:06,620 --> 00:41:06,630 combine that and bonding and bond 1367 00:41:06,630 --> 00:41:10,099 combine that and bonding and bond antibonding molecular orbitals 1368 00:41:10,099 --> 00:41:10,109 antibonding molecular orbitals 1369 00:41:10,109 --> 00:41:13,190 antibonding molecular orbitals now this explained something but I will 1370 00:41:13,190 --> 00:41:13,200 now this explained something but I will 1371 00:41:13,200 --> 00:41:29,319 now this explained something but I will just show you later now uh I should 1372 00:41:29,319 --> 00:41:29,329 1373 00:41:29,329 --> 00:41:34,970 actually what really happens in diatomic 1374 00:41:34,970 --> 00:41:34,980 actually what really happens in diatomic 1375 00:41:34,980 --> 00:41:37,250 actually what really happens in diatomic molecules particularly homonuclear 1376 00:41:37,250 --> 00:41:37,260 molecules particularly homonuclear 1377 00:41:37,260 --> 00:41:43,599 molecules particularly homonuclear diatomic molecules such as n 2o 2 c2 1378 00:41:43,599 --> 00:41:43,609 diatomic molecules such as n 2o 2 c2 1379 00:41:43,609 --> 00:41:48,500 diatomic molecules such as n 2o 2 c2 carbon again as fluorine to chlorine - 1380 00:41:48,500 --> 00:41:48,510 carbon again as fluorine to chlorine - 1381 00:41:48,510 --> 00:41:52,609 carbon again as fluorine to chlorine - those are a diatomic now the energy 1382 00:41:52,609 --> 00:41:52,619 those are a diatomic now the energy 1383 00:41:52,619 --> 00:41:57,400 those are a diatomic now the energy order of the orbitals are like this but 1384 00:41:57,400 --> 00:41:57,410 order of the orbitals are like this but 1385 00:41:57,410 --> 00:42:01,099 order of the orbitals are like this but when the energy difference between the 1386 00:42:01,099 --> 00:42:01,109 when the energy difference between the 1387 00:42:01,109 --> 00:42:07,339 when the energy difference between the 2s and 2p orbitals is small here what 1388 00:42:07,339 --> 00:42:07,349 2s and 2p orbitals is small here what 1389 00:42:07,349 --> 00:42:13,640 2s and 2p orbitals is small here what happens that this orbital Sigma 2 s and 1390 00:42:13,640 --> 00:42:13,650 happens that this orbital Sigma 2 s and 1391 00:42:13,650 --> 00:42:18,079 happens that this orbital Sigma 2 s and Sigma 2p which has the same symmetry but 1392 00:42:18,079 --> 00:42:18,089 Sigma 2p which has the same symmetry but 1393 00:42:18,089 --> 00:42:19,760 Sigma 2p which has the same symmetry but now when I say same symmetry it's 1394 00:42:19,760 --> 00:42:19,770 now when I say same symmetry it's 1395 00:42:19,770 --> 00:42:21,440 now when I say same symmetry it's different than the Sigma and PI type 1396 00:42:21,440 --> 00:42:21,450 different than the Sigma and PI type 1397 00:42:21,450 --> 00:42:23,599 different than the Sigma and PI type symmetry actually the real symmetry wise 1398 00:42:23,599 --> 00:42:23,609 symmetry actually the real symmetry wise 1399 00:42:23,609 --> 00:42:27,680 symmetry actually the real symmetry wise they're both G type orbitals G symmetry 1400 00:42:27,680 --> 00:42:27,690 they're both G type orbitals G symmetry 1401 00:42:27,690 --> 00:42:30,470 they're both G type orbitals G symmetry orbitals they interact with each other 1402 00:42:30,470 --> 00:42:30,480 orbitals they interact with each other 1403 00:42:30,480 --> 00:42:32,870 orbitals they interact with each other and when they interact with each other 1404 00:42:32,870 --> 00:42:32,880 and when they interact with each other 1405 00:42:32,880 --> 00:42:35,240 and when they interact with each other the energy of this becomes higher up 1406 00:42:35,240 --> 00:42:35,250 the energy of this becomes higher up 1407 00:42:35,250 --> 00:42:37,910 the energy of this becomes higher up here pushed up and the energy of that is 1408 00:42:37,910 --> 00:42:37,920 here pushed up and the energy of that is 1409 00:42:37,920 --> 00:42:44,980 here pushed up and the energy of that is also lowered like this right and this 1410 00:42:44,980 --> 00:42:44,990 1411 00:42:44,990 --> 00:42:48,620 this figure actually shows that you see 1412 00:42:48,620 --> 00:42:48,630 this figure actually shows that you see 1413 00:42:48,630 --> 00:42:52,069 this figure actually shows that you see again those two orbitals they have this 1414 00:42:52,069 --> 00:42:52,079 again those two orbitals they have this 1415 00:42:52,079 --> 00:42:54,799 again those two orbitals they have this as I show you that becomes more stable 1416 00:42:54,799 --> 00:42:54,809 as I show you that becomes more stable 1417 00:42:54,809 --> 00:42:56,929 as I show you that becomes more stable and that become the that becomes more 1418 00:42:56,929 --> 00:42:56,939 and that become the that becomes more 1419 00:42:56,939 --> 00:43:01,309 and that become the that becomes more unstable as a result what happens Sigma 1420 00:43:01,309 --> 00:43:01,319 unstable as a result what happens Sigma 1421 00:43:01,319 --> 00:43:07,459 unstable as a result what happens Sigma 2p zet orbitals energy becomes above the 1422 00:43:07,459 --> 00:43:07,469 2p zet orbitals energy becomes above the 1423 00:43:07,469 --> 00:43:14,150 2p zet orbitals energy becomes above the PI 2p orbitals again let me show it over 1424 00:43:14,150 --> 00:43:14,160 PI 2p orbitals again let me show it over 1425 00:43:14,160 --> 00:43:16,160 PI 2p orbitals again let me show it over here like this that simply means that 1426 00:43:16,160 --> 00:43:16,170 here like this that simply means that 1427 00:43:16,170 --> 00:43:19,130 here like this that simply means that the energy of this orbital becomes over 1428 00:43:19,130 --> 00:43:19,140 the energy of this orbital becomes over 1429 00:43:19,140 --> 00:43:22,459 the energy of this orbital becomes over here and that above this as a matter of 1430 00:43:22,459 --> 00:43:22,469 here and that above this as a matter of 1431 00:43:22,469 --> 00:43:25,099 here and that above this as a matter of fact and then I will have simply the 1432 00:43:25,099 --> 00:43:25,109 fact and then I will have simply the 1433 00:43:25,109 --> 00:43:27,229 fact and then I will have simply the order of the orbitals molecular orbitals 1434 00:43:27,229 --> 00:43:27,239 order of the orbitals molecular orbitals 1435 00:43:27,239 --> 00:43:30,410 order of the orbitals molecular orbitals Sigma 2 s Sigma 2 s star this will be 1436 00:43:30,410 --> 00:43:30,420 Sigma 2 s Sigma 2 s star this will be 1437 00:43:30,420 --> 00:43:35,900 Sigma 2 s Sigma 2 s star this will be lower than the PI 2p then the Sigma 2p 1438 00:43:35,900 --> 00:43:35,910 lower than the PI 2p then the Sigma 2p 1439 00:43:35,910 --> 00:43:39,380 lower than the PI 2p then the Sigma 2p again this this part stays the same 2p + 1440 00:43:39,380 --> 00:43:39,390 again this this part stays the same 2p + 1441 00:43:39,390 --> 00:43:44,419 again this this part stays the same 2p + 2 PZ so when we put the electrons into 1442 00:43:44,419 --> 00:43:44,429 2 PZ so when we put the electrons into 1443 00:43:44,429 --> 00:43:46,130 2 PZ so when we put the electrons into those Phil the electrons into those 1444 00:43:46,130 --> 00:43:46,140 those Phil the electrons into those 1445 00:43:46,140 --> 00:43:50,499 those Phil the electrons into those orbitals in diatomic molecule actually 1446 00:43:50,499 --> 00:43:50,509 orbitals in diatomic molecule actually 1447 00:43:50,509 --> 00:43:53,569 orbitals in diatomic molecule actually the number of unpaired electron changes 1448 00:43:53,569 --> 00:43:53,579 the number of unpaired electron changes 1449 00:43:53,579 --> 00:43:56,539 the number of unpaired electron changes due to the change of the energy order of 1450 00:43:56,539 --> 00:43:56,549 due to the change of the energy order of 1451 00:43:56,549 --> 00:44:00,679 due to the change of the energy order of that Sigma 2 P and Sigma 2 pi orbitals 1452 00:44:00,679 --> 00:44:00,689 that Sigma 2 P and Sigma 2 pi orbitals 1453 00:44:00,689 --> 00:44:03,429 that Sigma 2 P and Sigma 2 pi orbitals here are the examples you see again here 1454 00:44:03,429 --> 00:44:03,439 here are the examples you see again here 1455 00:44:03,439 --> 00:44:09,259 here are the examples you see again here this is the boron diatomic boron boron 1456 00:44:09,259 --> 00:44:09,269 this is the boron diatomic boron boron 1457 00:44:09,269 --> 00:44:12,799 this is the boron diatomic boron boron molecule carbon molecule diatomic carbon 1458 00:44:12,799 --> 00:44:12,809 molecule carbon molecule diatomic carbon 1459 00:44:12,809 --> 00:44:16,039 molecule carbon molecule diatomic carbon molecule and the diatomic nitrogen 1460 00:44:16,039 --> 00:44:16,049 molecule and the diatomic nitrogen 1461 00:44:16,049 --> 00:44:19,519 molecule and the diatomic nitrogen molecule the order energy order of the 1462 00:44:19,519 --> 00:44:19,529 molecule the order energy order of the 1463 00:44:19,529 --> 00:44:25,759 molecule the order energy order of the Sigma and PI 2 P PI and 2 P Sigma 1464 00:44:25,759 --> 00:44:25,769 Sigma and PI 2 P PI and 2 P Sigma 1465 00:44:25,769 --> 00:44:28,209 Sigma and PI 2 P PI and 2 P Sigma changed right there above these are 1466 00:44:28,209 --> 00:44:28,219 changed right there above these are 1467 00:44:28,219 --> 00:44:31,609 changed right there above these are regular as in the figure here again 1468 00:44:31,609 --> 00:44:31,619 regular as in the figure here again 1469 00:44:31,619 --> 00:44:35,959 regular as in the figure here again right this is the 2p no I should say 1470 00:44:35,959 --> 00:44:35,969 right this is the 2p no I should say 1471 00:44:35,969 --> 00:44:39,739 right this is the 2p no I should say over here that Sigma goes over or stays 1472 00:44:39,739 --> 00:44:39,749 over here that Sigma goes over or stays 1473 00:44:39,749 --> 00:44:42,380 over here that Sigma goes over or stays there in these two K these three cases 1474 00:44:42,380 --> 00:44:42,390 there in these two K these three cases 1475 00:44:42,390 --> 00:44:47,900 there in these two K these three cases OH - f - n neon molecule we have simply 1476 00:44:47,900 --> 00:44:47,910 OH - f - n neon molecule we have simply 1477 00:44:47,910 --> 00:44:52,069 OH - f - n neon molecule we have simply Sigma 2 P lower energy than the Sigma 2 1478 00:44:52,069 --> 00:44:52,079 Sigma 2 P lower energy than the Sigma 2 1479 00:44:52,079 --> 00:44:55,459 Sigma 2 P lower energy than the Sigma 2 pi but here Sigma 2 pi is lower energy 1480 00:44:55,459 --> 00:44:55,469 pi but here Sigma 2 pi is lower energy 1481 00:44:55,469 --> 00:44:58,969 pi but here Sigma 2 pi is lower energy than the Sigma Pi 2 pi Xu lower energy 1482 00:44:58,969 --> 00:44:58,979 than the Sigma Pi 2 pi Xu lower energy 1483 00:44:58,979 --> 00:45:02,779 than the Sigma Pi 2 pi Xu lower energy than the Sigma 2 pi PI becomes more 1484 00:45:02,779 --> 00:45:02,789 than the Sigma 2 pi PI becomes more 1485 00:45:02,789 --> 00:45:05,390 than the Sigma 2 pi PI becomes more stable PI P orbitals 1486 00:45:05,390 --> 00:45:05,400 stable PI P orbitals 1487 00:45:05,400 --> 00:45:08,420 stable PI P orbitals Sigma P orbitals becomes about so when 1488 00:45:08,420 --> 00:45:08,430 Sigma P orbitals becomes about so when 1489 00:45:08,430 --> 00:45:10,570 Sigma P orbitals becomes about so when you put the electrons into these 1490 00:45:10,570 --> 00:45:10,580 you put the electrons into these 1491 00:45:10,580 --> 00:45:13,670 you put the electrons into these molecules diatomic molecules you see a 1492 00:45:13,670 --> 00:45:13,680 molecules diatomic molecules you see a 1493 00:45:13,680 --> 00:45:20,470 molecules diatomic molecules you see a game boron molecule will be paramagnetic 1494 00:45:20,470 --> 00:45:20,480 game boron molecule will be paramagnetic 1495 00:45:20,480 --> 00:45:23,810 game boron molecule will be paramagnetic right and carbon molecule will be 1496 00:45:23,810 --> 00:45:23,820 right and carbon molecule will be 1497 00:45:23,820 --> 00:45:26,840 right and carbon molecule will be diamagnetic nitrogen molecule will be 1498 00:45:26,840 --> 00:45:26,850 diamagnetic nitrogen molecule will be 1499 00:45:26,850 --> 00:45:29,390 diamagnetic nitrogen molecule will be diamagnetic oxygen molecule is 1500 00:45:29,390 --> 00:45:29,400 diamagnetic oxygen molecule is 1501 00:45:29,400 --> 00:45:31,700 diamagnetic oxygen molecule is paramagnetic as we have simply shown 1502 00:45:31,700 --> 00:45:31,710 paramagnetic as we have simply shown 1503 00:45:31,710 --> 00:45:34,210 paramagnetic as we have simply shown here two unpaired electron fluorine 1504 00:45:34,210 --> 00:45:34,220 here two unpaired electron fluorine 1505 00:45:34,220 --> 00:45:38,800 here two unpaired electron fluorine diamagnetic neon actually does not exist 1506 00:45:38,800 --> 00:45:38,810 diamagnetic neon actually does not exist 1507 00:45:38,810 --> 00:45:43,030 diamagnetic neon actually does not exist why because the bond order of neon 1508 00:45:43,030 --> 00:45:43,040 why because the bond order of neon 1509 00:45:43,040 --> 00:45:45,920 why because the bond order of neon molecule is zero just like the same as 1510 00:45:45,920 --> 00:45:45,930 molecule is zero just like the same as 1511 00:45:45,930 --> 00:45:48,500 molecule is zero just like the same as helium remember all of the noble gases 1512 00:45:48,500 --> 00:45:48,510 helium remember all of the noble gases 1513 00:45:48,510 --> 00:45:52,070 helium remember all of the noble gases do not form molecules they are in mono 1514 00:45:52,070 --> 00:45:52,080 do not form molecules they are in mono 1515 00:45:52,080 --> 00:45:54,040 do not form molecules they are in mono atomic form in the gas phase again 1516 00:45:54,040 --> 00:45:54,050 atomic form in the gas phase again 1517 00:45:54,050 --> 00:45:57,430 atomic form in the gas phase again because the bond order is 0 that means 1518 00:45:57,430 --> 00:45:57,440 because the bond order is 0 that means 1519 00:45:57,440 --> 00:46:01,340 because the bond order is 0 that means energetically there is no gain advantage 1520 00:46:01,340 --> 00:46:01,350 energetically there is no gain advantage 1521 00:46:01,350 --> 00:46:05,840 energetically there is no gain advantage in fact forming a molecule over the 1522 00:46:05,840 --> 00:46:05,850 in fact forming a molecule over the 1523 00:46:05,850 --> 00:46:15,380 in fact forming a molecule over the separate atoms ok this simply explains 1524 00:46:15,380 --> 00:46:15,390 separate atoms ok this simply explains 1525 00:46:15,390 --> 00:46:18,320 separate atoms ok this simply explains the diamagnetic and paramagnetic 1526 00:46:18,320 --> 00:46:18,330 the diamagnetic and paramagnetic 1527 00:46:18,330 --> 00:46:20,030 the diamagnetic and paramagnetic properties of the oxygen molecule this 1528 00:46:20,030 --> 00:46:20,040 properties of the oxygen molecule this 1529 00:46:20,040 --> 00:46:23,630 properties of the oxygen molecule this is again shows how the oxygen molecular 1530 00:46:23,630 --> 00:46:23,640 is again shows how the oxygen molecular 1531 00:46:23,640 --> 00:46:26,660 is again shows how the oxygen molecular oxygen is paramagnetic if you simply 1532 00:46:26,660 --> 00:46:26,670 oxygen is paramagnetic if you simply 1533 00:46:26,670 --> 00:46:31,460 oxygen is paramagnetic if you simply take a liquid oxygen liquid oxygen and 1534 00:46:31,460 --> 00:46:31,470 take a liquid oxygen liquid oxygen and 1535 00:46:31,470 --> 00:46:34,340 take a liquid oxygen liquid oxygen and pour it on a magnet and you will see 1536 00:46:34,340 --> 00:46:34,350 pour it on a magnet and you will see 1537 00:46:34,350 --> 00:46:36,290 pour it on a magnet and you will see that it will be attracted by the 1538 00:46:36,290 --> 00:46:36,300 that it will be attracted by the 1539 00:46:36,300 --> 00:46:39,070 that it will be attracted by the magnetic field simply saying that the 1540 00:46:39,070 --> 00:46:39,080 magnetic field simply saying that the 1541 00:46:39,080 --> 00:46:43,250 magnetic field simply saying that the oxygen molecule is paramagnetic oxygen 1542 00:46:43,250 --> 00:46:43,260 oxygen molecule is paramagnetic oxygen 1543 00:46:43,260 --> 00:46:45,500 oxygen molecule is paramagnetic oxygen molecule is paramagnetic as the 1544 00:46:45,500 --> 00:46:45,510 molecule is paramagnetic as the 1545 00:46:45,510 --> 00:46:51,320 molecule is paramagnetic as the molecular orbital theory predicts it now 1546 00:46:51,320 --> 00:46:51,330 molecular orbital theory predicts it now 1547 00:46:51,330 --> 00:46:54,740 molecular orbital theory predicts it now when you have heteronuclear diatomic 1548 00:46:54,740 --> 00:46:54,750 when you have heteronuclear diatomic 1549 00:46:54,750 --> 00:46:57,200 when you have heteronuclear diatomic molecules that means instead of two 1550 00:46:57,200 --> 00:46:57,210 molecules that means instead of two 1551 00:46:57,210 --> 00:46:59,060 molecules that means instead of two nitrogen to oxygen what happens if you 1552 00:46:59,060 --> 00:46:59,070 nitrogen to oxygen what happens if you 1553 00:46:59,070 --> 00:47:01,160 nitrogen to oxygen what happens if you have one nitrogen and one oxygen for 1554 00:47:01,160 --> 00:47:01,170 have one nitrogen and one oxygen for 1555 00:47:01,170 --> 00:47:03,830 have one nitrogen and one oxygen for example or one carbon and one oxygen now 1556 00:47:03,830 --> 00:47:03,840 example or one carbon and one oxygen now 1557 00:47:03,840 --> 00:47:05,210 example or one carbon and one oxygen now what will change 1558 00:47:05,210 --> 00:47:05,220 what will change 1559 00:47:05,220 --> 00:47:07,310 what will change remember when you change the atoms this 1560 00:47:07,310 --> 00:47:07,320 remember when you change the atoms this 1561 00:47:07,320 --> 00:47:09,170 remember when you change the atoms this is nitrogen this is the oxygen this is 1562 00:47:09,170 --> 00:47:09,180 is nitrogen this is the oxygen this is 1563 00:47:09,180 --> 00:47:12,020 is nitrogen this is the oxygen this is the enno molecule for example and the 1564 00:47:12,020 --> 00:47:12,030 the enno molecule for example and the 1565 00:47:12,030 --> 00:47:14,240 the enno molecule for example and the only thing will change is the energies 1566 00:47:14,240 --> 00:47:14,250 only thing will change is the energies 1567 00:47:14,250 --> 00:47:18,250 only thing will change is the energies of the 2s and 2p orbitals like this 1568 00:47:18,250 --> 00:47:18,260 of the 2s and 2p orbitals like this 1569 00:47:18,260 --> 00:47:20,500 of the 2s and 2p orbitals like this you see again in this case the oxygen 1570 00:47:20,500 --> 00:47:20,510 you see again in this case the oxygen 1571 00:47:20,510 --> 00:47:23,020 you see again in this case the oxygen atom the 2's orbital energy wise is 1572 00:47:23,020 --> 00:47:23,030 atom the 2's orbital energy wise is 1573 00:47:23,030 --> 00:47:24,430 atom the 2's orbital energy wise is lower than the 2's orbital in the 1574 00:47:24,430 --> 00:47:24,440 lower than the 2's orbital in the 1575 00:47:24,440 --> 00:47:26,890 lower than the 2's orbital in the nitrogen same is true for the P but 1576 00:47:26,890 --> 00:47:26,900 nitrogen same is true for the P but 1577 00:47:26,900 --> 00:47:28,990 nitrogen same is true for the P but there not much difference again you know 1578 00:47:28,990 --> 00:47:29,000 there not much difference again you know 1579 00:47:29,000 --> 00:47:31,420 there not much difference again you know just a little bit more stable and they 1580 00:47:31,420 --> 00:47:31,430 just a little bit more stable and they 1581 00:47:31,430 --> 00:47:33,400 just a little bit more stable and they will combine exactly the same phase 1582 00:47:33,400 --> 00:47:33,410 will combine exactly the same phase 1583 00:47:33,410 --> 00:47:36,040 will combine exactly the same phase fashion as homonuclear diatomic molecule 1584 00:47:36,040 --> 00:47:36,050 fashion as homonuclear diatomic molecule 1585 00:47:36,050 --> 00:47:39,700 fashion as homonuclear diatomic molecule to form bonding and anti-bonding 1586 00:47:39,700 --> 00:47:39,710 to form bonding and anti-bonding 1587 00:47:39,710 --> 00:47:42,760 to form bonding and anti-bonding molecular orbitals and the electrons in 1588 00:47:42,760 --> 00:47:42,770 molecular orbitals and the electrons in 1589 00:47:42,770 --> 00:47:45,220 molecular orbitals and the electrons in the atomic orbitals will simply fill in 1590 00:47:45,220 --> 00:47:45,230 the atomic orbitals will simply fill in 1591 00:47:45,230 --> 00:47:48,490 the atomic orbitals will simply fill in to these molecular orbitals like in this 1592 00:47:48,490 --> 00:47:48,500 to these molecular orbitals like in this 1593 00:47:48,500 --> 00:47:53,350 to these molecular orbitals like in this case for the nitrogen and O molecule you 1594 00:47:53,350 --> 00:47:53,360 case for the nitrogen and O molecule you 1595 00:47:53,360 --> 00:47:56,440 case for the nitrogen and O molecule you see there is one unpaired electron there 1596 00:47:56,440 --> 00:47:56,450 see there is one unpaired electron there 1597 00:47:56,450 --> 00:47:59,590 see there is one unpaired electron there now if you calculate the bond order for 1598 00:47:59,590 --> 00:47:59,600 now if you calculate the bond order for 1599 00:47:59,600 --> 00:48:01,900 now if you calculate the bond order for the N o molecule for the nitrogen 1600 00:48:01,900 --> 00:48:01,910 the N o molecule for the nitrogen 1601 00:48:01,910 --> 00:48:06,070 the N o molecule for the nitrogen remember it was 3 and for the N o 1602 00:48:06,070 --> 00:48:06,080 remember it was 3 and for the N o 1603 00:48:06,080 --> 00:48:09,100 remember it was 3 and for the N o molecule the number of bonding electrons 1604 00:48:09,100 --> 00:48:09,110 molecule the number of bonding electrons 1605 00:48:09,110 --> 00:48:12,460 molecule the number of bonding electrons anti bonding electron becomes 5 and 10 - 1606 00:48:12,460 --> 00:48:12,470 anti bonding electron becomes 5 and 10 - 1607 00:48:12,470 --> 00:48:14,890 anti bonding electron becomes 5 and 10 - 5 - there will be 2 point 5 so you can 1608 00:48:14,890 --> 00:48:14,900 5 - there will be 2 point 5 so you can 1609 00:48:14,900 --> 00:48:17,080 5 - there will be 2 point 5 so you can calculate the bond order for n o it will 1610 00:48:17,080 --> 00:48:17,090 calculate the bond order for n o it will 1611 00:48:17,090 --> 00:48:27,820 calculate the bond order for n o it will be 2 point 5 again right 2 point 5 okay 1612 00:48:27,820 --> 00:48:27,830 be 2 point 5 again right 2 point 5 okay 1613 00:48:27,830 --> 00:48:29,680 be 2 point 5 again right 2 point 5 okay this is the end of this chapter any 1614 00:48:29,680 --> 00:48:29,690 this is the end of this chapter any 1615 00:48:29,690 --> 00:48:45,950 this is the end of this chapter any questions yes 1616 00:48:45,950 --> 00:48:45,960 1617 00:48:45,960 --> 00:48:54,640 if they have one yes at the same spin oh 1618 00:48:54,640 --> 00:48:54,650 if they have one yes at the same spin oh 1619 00:48:54,650 --> 00:48:57,770 if they have one yes at the same spin oh that doesn't doesn't matter because the 1620 00:48:57,770 --> 00:48:57,780 that doesn't doesn't matter because the 1621 00:48:57,780 --> 00:48:59,750 that doesn't doesn't matter because the electrons in the hydrogen anthem may be 1622 00:48:59,750 --> 00:48:59,760 electrons in the hydrogen anthem may be 1623 00:48:59,760 --> 00:49:01,760 electrons in the hydrogen anthem may be in different spins like this but when 1624 00:49:01,760 --> 00:49:01,770 in different spins like this but when 1625 00:49:01,770 --> 00:49:05,720 in different spins like this but when they form a molecule when those two goes 1626 00:49:05,720 --> 00:49:05,730 they form a molecule when those two goes 1627 00:49:05,730 --> 00:49:07,700 they form a molecule when those two goes into the bonding molecular orbitals they 1628 00:49:07,700 --> 00:49:07,710 into the bonding molecular orbitals they 1629 00:49:07,710 --> 00:49:10,010 into the bonding molecular orbitals they have to pair up they have to pair up 1630 00:49:10,010 --> 00:49:10,020 have to pair up they have to pair up 1631 00:49:10,020 --> 00:49:13,880 have to pair up they have to pair up again just like the same as the atomic 1632 00:49:13,880 --> 00:49:13,890 again just like the same as the atomic 1633 00:49:13,890 --> 00:49:16,760 again just like the same as the atomic orbital if you put three electrons in 1634 00:49:16,760 --> 00:49:16,770 orbital if you put three electrons in 1635 00:49:16,770 --> 00:49:20,120 orbital if you put three electrons in one orbital it has to be paired up you 1636 00:49:20,120 --> 00:49:20,130 one orbital it has to be paired up you 1637 00:49:20,130 --> 00:49:22,040 one orbital it has to be paired up you can't put them up like this because 1638 00:49:22,040 --> 00:49:22,050 can't put them up like this because 1639 00:49:22,050 --> 00:49:26,930 can't put them up like this because that's again in case of atoms against 1640 00:49:26,930 --> 00:49:26,940 that's again in case of atoms against 1641 00:49:26,940 --> 00:49:28,430 that's again in case of atoms against the Pauli exclusion principle remember 1642 00:49:28,430 --> 00:49:28,440 the Pauli exclusion principle remember 1643 00:49:28,440 --> 00:49:30,770 the Pauli exclusion principle remember you can't have two electrons in the same 1644 00:49:30,770 --> 00:49:30,780 you can't have two electrons in the same 1645 00:49:30,780 --> 00:49:32,780 you can't have two electrons in the same orbital with the same spin but if there 1646 00:49:32,780 --> 00:49:32,790 orbital with the same spin but if there 1647 00:49:32,790 --> 00:49:34,370 orbital with the same spin but if there are different orbitals they will be Hans 1648 00:49:34,370 --> 00:49:34,380 are different orbitals they will be Hans 1649 00:49:34,380 --> 00:49:37,010 are different orbitals they will be Hans rule says that they will have the same 1650 00:49:37,010 --> 00:49:37,020 rule says that they will have the same 1651 00:49:37,020 --> 00:49:44,410 rule says that they will have the same spin directions actually okay oh I guess 1652 00:49:44,410 --> 00:49:44,420 spin directions actually okay oh I guess 1653 00:49:44,420 --> 00:49:48,980 spin directions actually okay oh I guess this is the end of this hour we will 1654 00:49:48,980 --> 00:49:48,990 this is the end of this hour we will 1655 00:49:48,990 --> 00:49:51,860 this is the end of this hour we will start the next chapter next hour 1656 00:49:51,860 --> 00:49:51,870 start the next chapter next hour 1657 00:49:51,870 --> 00:49:55,850 start the next chapter next hour let's have 10 minutes break now but 1658 00:49:55,850 --> 00:49:55,860 let's have 10 minutes break now but 1659 00:49:55,860 --> 00:49:59,600 let's have 10 minutes break now but please make it exactly ten minutes