1 00:00:01,713 --> 00:00:02,933 - Now that we understand the four 2 00:00:02,933 --> 00:00:04,493 quantum numbers, let's get some more 3 00:00:04,493 --> 00:00:06,353 practice using the quantum numbers 4 00:00:06,353 --> 00:00:08,393 and thinking about the first four shells, 5 00:00:08,393 --> 00:00:10,573 the first four energy levels. 6 00:00:10,573 --> 00:00:12,953 So we'll start with n is equal to one. 7 00:00:12,953 --> 00:00:14,473 So when n is equal to one, 8 00:00:14,473 --> 00:00:16,769 the principle quantum number is equal to one, 9 00:00:16,769 --> 00:00:18,751 we're talking about the first energy level 10 00:00:18,751 --> 00:00:20,751 or the first shell. 11 00:00:20,751 --> 00:00:23,964 The angular momentum quantum number depends upon 12 00:00:23,964 --> 00:00:25,844 the principle quantum number and so 13 00:00:25,844 --> 00:00:27,824 when n is equal to one, let's think about 14 00:00:27,824 --> 00:00:30,444 the allowed values for l. 15 00:00:30,444 --> 00:00:33,604 So l goes from zero, one and all 16 00:00:33,604 --> 00:00:36,065 the way up to n minus one. 17 00:00:36,065 --> 00:00:38,666 Well n minus one, if n is equal to one 18 00:00:38,666 --> 00:00:41,096 and minus one, one minus one is equal to zero 19 00:00:41,096 --> 00:00:43,856 and so that's the only allowed value 20 00:00:43,856 --> 00:00:46,676 for the angular momentum quantum number. 21 00:00:46,676 --> 00:00:48,756 And we know l is equal to zero 22 00:00:48,756 --> 00:00:50,656 refers to an s orbital. 23 00:00:50,656 --> 00:00:52,997 So we're talking about an s orbital here. 24 00:00:52,997 --> 00:00:54,697 Alright, the next quantum number is 25 00:00:54,697 --> 00:00:56,677 the magnetic quantum number. 26 00:00:56,677 --> 00:00:57,817 So ml. 27 00:00:57,817 --> 00:00:59,037 So the magnetic quantum number 28 00:00:59,037 --> 00:01:02,057 depends on the angular momentum quantum number 29 00:01:02,057 --> 00:01:05,817 and it goes from negative l to positive l. 30 00:01:05,817 --> 00:01:07,518 So if l is equal to zero, 31 00:01:07,518 --> 00:01:09,479 we only get one value for 32 00:01:09,479 --> 00:01:10,759 the magnetic quantum number. 33 00:01:10,759 --> 00:01:12,179 If l is equal to zero, the only possible 34 00:01:12,179 --> 00:01:14,039 value we could get is zero. 35 00:01:14,039 --> 00:01:16,419 And remember, this tells us the orientation. 36 00:01:16,419 --> 00:01:18,559 So we only have one possible orientation. 37 00:01:18,559 --> 00:01:20,879 We have only one s orbital. 38 00:01:20,879 --> 00:01:22,959 So there's an s orbital, there's only 39 00:01:22,959 --> 00:01:24,719 one of them here. 40 00:01:24,719 --> 00:01:28,120 We know an s orbital is shaped like a sphere. 41 00:01:28,120 --> 00:01:30,373 So remember, an orbital is the region 42 00:01:30,373 --> 00:01:33,934 where you're most likely to find an electron here. 43 00:01:33,934 --> 00:01:36,553 So there's a total of one orbital 44 00:01:36,553 --> 00:01:38,973 in the first energy level and you could 45 00:01:38,973 --> 00:01:41,285 have gotten that by using n squared. 46 00:01:41,285 --> 00:01:43,166 So when n is equal to one, 47 00:01:43,166 --> 00:01:45,006 one squared is equal to one, 48 00:01:45,006 --> 00:01:47,058 that's the total number of orbitals 49 00:01:47,058 --> 00:01:50,420 that you're going to find in the first energy level here. 50 00:01:50,420 --> 00:01:53,841 Let's move on to electrons in the orbital. 51 00:01:53,841 --> 00:01:56,082 So you can fit a maximum 52 00:01:56,082 --> 00:01:59,163 of two electrons in one orbital. 53 00:01:59,163 --> 00:02:00,723 So the fourth quantum number, 54 00:02:00,723 --> 00:02:02,164 alright, the fourth quantum number says, 55 00:02:02,164 --> 00:02:04,533 the spin of an electron can either be positive 56 00:02:04,533 --> 00:02:06,567 one half or it can be negative one half. 57 00:02:06,567 --> 00:02:08,249 And so if you have two electrons 58 00:02:08,249 --> 00:02:10,387 in one orbital, one electron has to spin 59 00:02:10,387 --> 00:02:12,187 a positive one half and one electron 60 00:02:12,187 --> 00:02:14,327 has a spin of negative one half. 61 00:02:14,327 --> 00:02:16,667 So there's a maximum of two electrons 62 00:02:16,667 --> 00:02:19,047 in one orbital, we have a maximum of 63 00:02:19,047 --> 00:02:21,663 two electrons in this one s orbital 64 00:02:21,663 --> 00:02:23,383 in the first energy level. 65 00:02:23,383 --> 00:02:25,618 And since that's the only orbital 66 00:02:25,618 --> 00:02:27,580 in this energy level or this shell, 67 00:02:27,580 --> 00:02:30,418 that's also the total number of electrons in the shell. 68 00:02:30,418 --> 00:02:32,628 So the total number of electrons 69 00:02:32,628 --> 00:02:33,988 is equal to two. 70 00:02:33,988 --> 00:02:36,219 And you could have gotten that using two n squared. 71 00:02:36,219 --> 00:02:38,879 So if n is equal to one, so one squared 72 00:02:38,879 --> 00:02:42,759 is equal to one times two which is equal to two. 73 00:02:42,759 --> 00:02:44,799 So that's the first energy level 74 00:02:44,799 --> 00:02:46,479 or the first shell. 75 00:02:46,479 --> 00:02:48,079 Let's move on to the second shell. 76 00:02:48,079 --> 00:02:51,422 So this is where n is equal to two. 77 00:02:51,422 --> 00:02:52,984 So if n is equal to two, 78 00:02:52,984 --> 00:02:55,262 the principle quantum number is equal to two, 79 00:02:55,262 --> 00:02:57,202 the angular momentum quantum number, 80 00:02:57,202 --> 00:02:59,202 what are the allowed values? 81 00:02:59,202 --> 00:03:00,702 Well you start with zero and you go 82 00:03:00,702 --> 00:03:03,004 all the way up to n minus one. 83 00:03:03,004 --> 00:03:05,020 So we start with zero, n minus one, 84 00:03:05,020 --> 00:03:07,692 that would be two minus one, that would be one. 85 00:03:07,692 --> 00:03:09,849 So we go from zero and then we go to one 86 00:03:09,849 --> 00:03:10,830 and then we have to stop. 87 00:03:10,830 --> 00:03:12,624 So we have only two allowed values 88 00:03:12,624 --> 00:03:14,947 for the angular momentum quantum number. 89 00:03:14,947 --> 00:03:16,585 So if you have n equal to two, 90 00:03:16,585 --> 00:03:18,825 you get two allowed values here. 91 00:03:18,825 --> 00:03:20,085 We already talked about what 92 00:03:20,085 --> 00:03:21,625 l is equal to zero means, 93 00:03:21,625 --> 00:03:24,868 l is equal to zero refers to an s orbital. 94 00:03:25,314 --> 00:03:26,458 And there's one s orbital. 95 00:03:26,458 --> 00:03:28,032 So in the second energy level, 96 00:03:28,032 --> 00:03:29,673 there's another s orbital. 97 00:03:29,673 --> 00:03:31,373 This is different from the s orbital 98 00:03:31,373 --> 00:03:32,893 in the first energy level 99 00:03:32,893 --> 00:03:34,414 that we just talked about. 100 00:03:34,414 --> 00:03:36,034 So there's another s orbital here. 101 00:03:36,034 --> 00:03:39,882 It too is shaped liked a sphere. 102 00:03:40,851 --> 00:03:42,952 What I drew here is misleading. 103 00:03:42,952 --> 00:03:44,717 I drew this as being a little bit smaller 104 00:03:44,717 --> 00:03:45,917 then the one before. 105 00:03:45,917 --> 00:03:48,538 Remember, when n is equal to two, you're further away. 106 00:03:48,538 --> 00:03:50,718 You're electron is on average further away 107 00:03:50,718 --> 00:03:52,939 from your nucleus here, 108 00:03:52,939 --> 00:03:55,629 l is equal to one so if l is equal to one, 109 00:03:55,629 --> 00:03:57,049 what is the allowed values for 110 00:03:57,049 --> 00:03:58,410 the magnetic quantum number? 111 00:03:58,410 --> 00:04:00,780 So remember, the magnetic quantum number 112 00:04:01,364 --> 00:04:03,243 goes from negative l to positive l. 113 00:04:03,243 --> 00:04:05,221 So negative l would be negative one, 114 00:04:05,221 --> 00:04:07,201 and then we include zero and then 115 00:04:07,201 --> 00:04:08,721 we go to positive one. 116 00:04:08,721 --> 00:04:11,616 So there are three possible values 117 00:04:11,616 --> 00:04:12,616 for the magnetic quantum number. 118 00:04:12,616 --> 00:04:15,179 One, two, three, the magnetic quantum number 119 00:04:15,179 --> 00:04:17,036 told us the orientation so there are 120 00:04:17,036 --> 00:04:19,117 three different orientations. 121 00:04:19,118 --> 00:04:21,098 And we talked about l is equal to one 122 00:04:21,098 --> 00:04:23,301 is referring to a p orbital which 123 00:04:23,301 --> 00:04:25,559 is shaped like a dumbbell. 124 00:04:25,559 --> 00:04:26,919 So we have three different orientations, 125 00:04:26,919 --> 00:04:29,361 we have three different p orbitals 126 00:04:29,361 --> 00:04:31,318 in the second energy level. 127 00:04:31,318 --> 00:04:33,338 One of them goes along the x-axis, 128 00:04:33,338 --> 00:04:35,488 one of them the y and one of them the z. 129 00:04:35,488 --> 00:04:38,169 So we talked about this in the previous video. 130 00:04:38,169 --> 00:04:41,869 So a total of three p orbitals here. 131 00:04:41,869 --> 00:04:43,549 So how many orbitals are there 132 00:04:43,549 --> 00:04:45,189 in the second energy level? 133 00:04:45,189 --> 00:04:48,091 Well we have one s orbital and three p orbitals. 134 00:04:48,091 --> 00:04:50,291 So one plus three gives us four. 135 00:04:50,291 --> 00:04:52,351 We could have done this math, 136 00:04:52,351 --> 00:04:56,352 n squared, so two is n squared 137 00:04:56,352 --> 00:04:58,192 which gives us four. 138 00:04:58,192 --> 00:04:59,855 Alright, let's do electrons now. 139 00:04:59,855 --> 00:05:03,553 So four, let's go back to the s orbital here. 140 00:05:03,553 --> 00:05:05,175 Remember, there's one orbital so we can 141 00:05:05,175 --> 00:05:08,313 fit a maximum of two electrons in one orbital. 142 00:05:08,313 --> 00:05:12,705 For the p orbitals, we have three p orbitals. 143 00:05:13,643 --> 00:05:15,174 If each p orbital's holding a maximum 144 00:05:15,174 --> 00:05:17,332 of two electrons, three times two 145 00:05:17,332 --> 00:05:20,803 gives us six, so we have a total of 146 00:05:20,803 --> 00:05:24,243 eight electrons in the second energy level. 147 00:05:24,243 --> 00:05:25,923 So eight electrons and we can get that 148 00:05:25,923 --> 00:05:27,344 from two n squared again right? 149 00:05:27,344 --> 00:05:29,326 Because if n is equal to two, 150 00:05:29,326 --> 00:05:31,424 square that and you get four, 151 00:05:31,424 --> 00:05:34,354 multiply that by two and you get eight. 152 00:05:34,354 --> 00:05:37,445 Alright, let's go to the third energy level 153 00:05:37,445 --> 00:05:39,087 or the third shell here. 154 00:05:39,087 --> 00:05:42,145 So when n is equal to three 155 00:05:42,145 --> 00:05:43,945 what are the allowed values for 156 00:05:43,945 --> 00:05:46,205 the angular momentum quantum number l? 157 00:05:46,205 --> 00:05:48,367 So remember l goes from zero all the way 158 00:05:48,367 --> 00:05:50,245 up to n minus one. 159 00:05:50,245 --> 00:05:53,839 So l goes from zero all the way to n minus one. 160 00:05:53,839 --> 00:05:56,120 So l is equal to zero, l is equal to one 161 00:05:56,120 --> 00:06:00,421 and l is equal to two because three minus one 162 00:06:00,421 --> 00:06:03,883 is equal to two, so if we have n is equal to three, 163 00:06:03,883 --> 00:06:06,683 we have three possible values for l. 164 00:06:06,683 --> 00:06:08,403 Zero, one and two. 165 00:06:08,403 --> 00:06:09,363 We already talked about 166 00:06:09,363 --> 00:06:10,983 what l is equal to zero means, 167 00:06:10,983 --> 00:06:13,344 l is equal to zero is an s orbital 168 00:06:13,344 --> 00:06:15,174 and there's one of them, 169 00:06:15,174 --> 00:06:17,266 l is equal to one is a p orbital 170 00:06:17,266 --> 00:06:19,656 and with three allowed values 171 00:06:19,656 --> 00:06:21,437 for the magnetic quantum number, 172 00:06:21,437 --> 00:06:23,298 we can have three p orbitals 173 00:06:23,298 --> 00:06:25,758 in the third energy level. 174 00:06:25,758 --> 00:06:28,379 So let's focus in on l is equal to two. 175 00:06:28,379 --> 00:06:30,079 So when l is equal to two, 176 00:06:30,079 --> 00:06:31,520 what are the allowed values for 177 00:06:31,520 --> 00:06:33,640 the magnetic quantum number? 178 00:06:33,640 --> 00:06:36,520 Well those go from negative l to positive l. 179 00:06:36,520 --> 00:06:39,300 So if l is equal to two, let me use 180 00:06:39,300 --> 00:06:40,440 a different color here. 181 00:06:40,440 --> 00:06:42,320 So if l is equal to two, we could go 182 00:06:42,320 --> 00:06:47,320 negative two, negative one, zero, one and two. 183 00:06:48,020 --> 00:06:52,020 So that's a total of one, two, three, four, 184 00:06:52,020 --> 00:06:53,841 five, five values. 185 00:06:53,841 --> 00:06:56,701 So five different orientations for this orbital 186 00:06:56,701 --> 00:06:58,381 and when l is equal to two, 187 00:06:58,381 --> 00:07:00,842 we call this a d orbital. 188 00:07:00,842 --> 00:07:02,822 So five different orientations 189 00:07:02,822 --> 00:07:05,122 so five d orbitals. 190 00:07:05,122 --> 00:07:07,082 So I'm going to write a five here. 191 00:07:07,082 --> 00:07:09,382 So the total number of orbitals that we have 192 00:07:09,382 --> 00:07:11,263 in this energy level, that would be 193 00:07:11,263 --> 00:07:14,854 one plus three plus five and so that's nine 194 00:07:14,854 --> 00:07:17,795 which we could have gotten from three squared. 195 00:07:17,795 --> 00:07:20,438 So the total number of orbitals equal to n squared, 196 00:07:20,438 --> 00:07:23,951 if n is equal to three, three squared gives us nine. 197 00:07:23,951 --> 00:07:26,491 Alright, how many electrons can we fit 198 00:07:26,491 --> 00:07:28,291 in each one of those orbitals? 199 00:07:28,291 --> 00:07:30,931 Well, let me once again use a different color. 200 00:07:30,931 --> 00:07:33,666 So we have the s orbital, we have one of those, 201 00:07:33,666 --> 00:07:35,727 so we can fit a maximum of two electrons 202 00:07:35,727 --> 00:07:37,387 into that s orbital. 203 00:07:37,387 --> 00:07:39,756 For the p orbitals in the third energy level, 204 00:07:39,756 --> 00:07:41,923 we have three of them, so each one of those orbitals 205 00:07:41,923 --> 00:07:43,643 could fit a maximum of two. 206 00:07:43,643 --> 00:07:45,841 So three times two gives us six 207 00:07:45,841 --> 00:07:49,015 and then we go to the d orbitals. 208 00:07:49,015 --> 00:07:50,344 Alright, so five orbitals. 209 00:07:50,344 --> 00:07:52,607 Each one can hold a maximum of two electrons 210 00:07:52,607 --> 00:07:55,827 so five times two gives us ten. 211 00:07:55,827 --> 00:07:58,070 So what's the total number of electrons 212 00:07:58,070 --> 00:08:00,762 that we can fit in this third shell here? 213 00:08:00,762 --> 00:08:02,082 So that would be two plus six 214 00:08:02,082 --> 00:08:04,297 plus ten, that's 18. 215 00:08:04,297 --> 00:08:05,798 Alright and again, we could have used 216 00:08:05,798 --> 00:08:07,498 this little formula over here. 217 00:08:07,498 --> 00:08:10,412 So two n squared, so if n is equal to three, 218 00:08:10,412 --> 00:08:14,553 square that that's nine times two, this gives us 18. 219 00:08:14,553 --> 00:08:19,454 Alright, let's do one more and before I do that, 220 00:08:19,454 --> 00:08:20,634 we already talked about the shape 221 00:08:20,634 --> 00:08:22,414 of an s orbital, we talked about the shape 222 00:08:22,414 --> 00:08:24,586 of a p orbital, when you get in to 223 00:08:24,586 --> 00:08:27,007 things like d orbitals, you start to get a little bit 224 00:08:27,007 --> 00:08:28,627 complicated and it's a little bit 225 00:08:28,627 --> 00:08:30,087 tricky for me to draw. 226 00:08:30,087 --> 00:08:31,647 So I'm not going to attempt do draw 227 00:08:31,647 --> 00:08:33,567 all the d orbitals in the five 228 00:08:33,567 --> 00:08:37,491 different orientations, so let's just move on 229 00:08:37,491 --> 00:08:40,589 to n is equal to four. 230 00:08:41,451 --> 00:08:46,015 I went ahead and rewrote what we were going for here. 231 00:08:46,015 --> 00:08:48,275 So we're going to go for n, 232 00:08:48,275 --> 00:08:50,515 so we're going for n is equal to four now, 233 00:08:50,515 --> 00:08:52,335 n is equal to four. 234 00:08:52,335 --> 00:08:54,397 What are the allowed values for l? 235 00:08:54,397 --> 00:08:57,577 So that's zero all the way up to n minus one. 236 00:08:57,577 --> 00:09:00,359 So l is equal to zero, l is equal to one, 237 00:09:00,359 --> 00:09:03,210 l is equal to two and then n minus one, 238 00:09:03,210 --> 00:09:05,424 that's four minus one, that's equal to three. 239 00:09:05,424 --> 00:09:10,064 So that's the last allowed value for l, 240 00:09:10,064 --> 00:09:12,044 the angular momentum quantum number. 241 00:09:12,044 --> 00:09:14,944 And once again, if you have four here, 242 00:09:14,944 --> 00:09:17,904 you get four allowed values. 243 00:09:17,904 --> 00:09:19,564 Alright, when l is equal to zero, 244 00:09:19,564 --> 00:09:21,285 we said that's an s orbital. 245 00:09:21,285 --> 00:09:24,966 When l is equal to one, we said that was a p orbital. 246 00:09:24,966 --> 00:09:26,246 When l is equal to two, 247 00:09:26,246 --> 00:09:28,105 we call that a d orbital 248 00:09:28,105 --> 00:09:29,585 and when l is equal to three, 249 00:09:29,585 --> 00:09:31,905 we're going to call this an f orbital. 250 00:09:31,905 --> 00:09:34,764 And s, p, d and f come from old 251 00:09:34,764 --> 00:09:37,995 nomenclature used in atomic spectroscopy 252 00:09:37,995 --> 00:09:39,475 and so it's kind of... 253 00:09:39,475 --> 00:09:41,197 It's not really used anymore but like 254 00:09:41,197 --> 00:09:43,297 the s, I think, used to stand for sharp 255 00:09:43,297 --> 00:09:46,497 and so that's where your letters come from here. 256 00:09:46,497 --> 00:09:48,717 We used them to think about the orbitals 257 00:09:48,717 --> 00:09:50,699 and the different shapes here. 258 00:09:50,699 --> 00:09:52,517 So an s orbital is shaped like a sphere, 259 00:09:52,517 --> 00:09:54,317 we know we have one of those. 260 00:09:54,317 --> 00:09:55,877 A p orbital is shaped like a dumbbell, 261 00:09:55,877 --> 00:09:57,817 we know we have three of those. 262 00:09:57,817 --> 00:09:59,777 D orbitals, we just talked about the fact 263 00:09:59,777 --> 00:10:01,847 that we have five of them. 264 00:10:01,847 --> 00:10:03,938 So five different possible values here fore 265 00:10:03,938 --> 00:10:06,098 the magnetic quantum number. 266 00:10:06,098 --> 00:10:08,921 So we have five d orbitals in 267 00:10:08,921 --> 00:10:11,140 the fourth energy level and then 268 00:10:11,140 --> 00:10:12,860 finally f alright? 269 00:10:12,860 --> 00:10:15,680 So an f orbital when l is equal to three, 270 00:10:15,680 --> 00:10:19,194 what are the allowed values for 271 00:10:20,101 --> 00:10:21,710 the magnetic quantum number? 272 00:10:21,710 --> 00:10:24,528 So ml, so what are the allowed values? 273 00:10:24,528 --> 00:10:27,948 Well they go from negative l to positive l. 274 00:10:27,948 --> 00:10:30,848 So if l is equal to three, 275 00:10:30,848 --> 00:10:31,988 I'm going to use a different color. 276 00:10:31,988 --> 00:10:34,188 If l is equal to three we could get 277 00:10:34,188 --> 00:10:37,789 negative three, negative two, negative one, 278 00:10:37,789 --> 00:10:41,049 zero, one, two and three. 279 00:10:41,049 --> 00:10:44,269 So how many different orbitals 280 00:10:44,269 --> 00:10:45,729 are we talking about now. 281 00:10:45,729 --> 00:10:48,109 That would be one, two, three, four, 282 00:10:48,109 --> 00:10:49,920 five, six, seven. 283 00:10:49,920 --> 00:10:54,920 So seven f orbitals in the fourth energy level. 284 00:10:55,801 --> 00:10:59,361 Alright, maximum number of electrons in the orbital. 285 00:10:59,361 --> 00:11:00,881 We have only one. 286 00:11:00,881 --> 00:11:03,382 Let me use, what color should I use here? 287 00:11:03,382 --> 00:11:04,462 Let's use magenta. 288 00:11:04,462 --> 00:11:07,903 So I have one s orbital, maximum two electrons. 289 00:11:07,903 --> 00:11:09,803 So two electrons here. 290 00:11:09,803 --> 00:11:12,244 Three p orbitals, two times three is six. 291 00:11:12,244 --> 00:11:15,224 Five d orbitals in the fourth shell 292 00:11:15,224 --> 00:11:16,514 or the fourth energy level, 293 00:11:16,514 --> 00:11:19,054 so five times two gives us ten. 294 00:11:19,054 --> 00:11:21,496 And then we just talked about f orbitals 295 00:11:21,496 --> 00:11:23,476 which would be way too difficult 296 00:11:23,476 --> 00:11:25,456 for me to draw so you can get some 297 00:11:25,456 --> 00:11:29,238 nice pictures of f orbitals online 298 00:11:29,238 --> 00:11:30,918 or in your textbook here. 299 00:11:30,918 --> 00:11:33,930 So if we have seven f orbitals, 300 00:11:33,930 --> 00:11:36,338 seven times two gives us a total 301 00:11:36,338 --> 00:11:38,694 of 14, so we could have a maximum 302 00:11:38,694 --> 00:11:42,911 of 14 electrons in the f orbitals. 303 00:11:42,911 --> 00:11:43,878 Alright, what's that total? 304 00:11:43,878 --> 00:11:45,158 So we add all those up. 305 00:11:45,158 --> 00:11:49,639 So two plus six plus ten plus 14, that's 32. 306 00:11:49,639 --> 00:11:53,360 So there's 32 electrons in the fourth shell, 307 00:11:53,360 --> 00:11:55,542 in the fourth energy level and once again, 308 00:11:55,542 --> 00:11:57,002 we could have used our formula here. 309 00:11:57,002 --> 00:12:00,122 So two n squared, so when n is equal to four, 310 00:12:00,122 --> 00:12:02,642 we square that and we get 16, 311 00:12:02,642 --> 00:12:05,703 we'll divide that by two and we get 32. 312 00:12:05,703 --> 00:12:08,183 And so hopefully this give you some 313 00:12:08,183 --> 00:12:11,164 experience playing with the quantum numbers. 314 00:12:11,164 --> 00:12:14,644 So you have to be, this is a very useful exercise. 315 00:12:14,644 --> 00:12:16,104 So just sit down and think about 316 00:12:16,104 --> 00:12:19,524 how the quantum numbers depend on each other. 317 00:12:19,524 --> 00:12:24,384 So l depends on n and ml, 318 00:12:24,384 --> 00:12:27,104 the magnetic quantum number depends on this. 319 00:12:27,104 --> 00:12:29,325 And so it's going to allow you 320 00:12:29,325 --> 00:12:32,266 to understand the periodic table 321 00:12:32,266 --> 00:00:00,000 and electron configurations.