00:01
All right, guys, we're new problem 80 of chapter 7.
00:03
So which are the following sets of quantum numbers are not allowed? for each incorrect set, why is it not correct? so our first set is n equals 3, l equals 3, ml equals 0, and ms equals negative 1 half.
00:28
So remember quantum number rules.
00:30
So n is equal to 1, 2, 3, 4, et cetera.
00:33
L is always less than n.
00:36
So if n is 1, 2, 3, 4, l is 0, 1, 2, 3, 8.
00:40
Etc.
00:43
Ml, that's the range between negative l and positive l, and ms is plus or minus 1 half.
00:49
So we have n equals 3, and l equals 3.
00:53
N cannot equal l.
00:56
So that makes this incorrect.
00:58
Ml can equal 0 and ms is negative 1⁄2, so that's fine.
01:04
So a is not allowed.
01:09
I'll denote that as n.
01:12
So let's go to b.
01:15
So n is equal to 4, l is equal to 3.
01:21
Ml is 2, and ms is negative 1 .5.
01:31
All right.
01:31
So we have n equals equal to 4.
01:34
That's fine.
01:35
Your first quantum number, you should always just strike n off the list first because that's always going to, because n can be anything as long as it's greater than zero.
01:46
L is equal to 3.
01:47
That's yes, it's lower than n.
01:50
Ml is equal 2.
01:53
That's fine.
01:54
It's between negative 3 and positive 3.
01:55
And ms is one half.
01:58
That's correct.
01:59
So we can write that as a.
02:09
So now, c, n is equal to four, l is equal to one.
02:15
Ml is one, and ms is positive one half.
02:23
So n is equal to four, that's fine.
02:26
L is one.
02:27
That's less than four.
02:28
That's correct.
02:29
At ml is fine...