## Quantum Numbers

Emilie_Paltrinieri_1K
Posts: 50
Joined: Wed Sep 30, 2020 10:07 pm

### Quantum Numbers

Could someone please explain what are the values that quantum numbers can have in relation to one another? I haven't clearly understood what Lavelle explained during lecture regarding the value that each quantum number can have (ex. l=n-1, ecc)

John Pham 3L
Posts: 107
Joined: Wed Sep 30, 2020 9:49 pm
Been upvoted: 4 times

### Re: Quantum Numbers

Principal Quantum Number can have the values n = 1, 2, 3, ... etc

Angular Momentum Quantum Number can have the values of l up to n - 1
- Example: If the principal quantum number is n = 4, then l could be any value up to 3 so it could be 0, 1, 2, or 3

- n = 1 can only have l = 0 which would be 1s subshell
- n = 2 can have l = 0 or 1 which means it could be a 2s or 2p subshell
- n =3 can have l = 0, 1, or 2, which means it could be a 3s, 3p, or 3d subshell

Magnetic Quantum Number can have values in the range of -l to +l
The equation could be 2l + 1

- Example: If the angular momentum quantum number is l = 2, then ml could be -2, -1, 0, +1, or +2
- The number of values possible for ml represents the number of orbitals in each subshell

- Example: Find the total number of electrons in a 3p orbital
- p is equal to l = 1
- It could have 3 values for ml: -1, 0, or 1
- Since it has 3 orbitals, it could hold 6 e-

Kamille Kibria 2A
Posts: 55
Joined: Wed Sep 30, 2020 9:52 pm

### Re: Quantum Numbers

first quantum #:
-principle quantum # (n)
- determines energy and size (shell)
-range: 1,2,3,4...
2nd quantum #:
-angular momentum of electron (l)
-range 0,1,2,...(n-1)
- if l=0 then it is in the s orbital, l=1 means p orbital, l=2 means d orbital, l=3 means f orbital
3rd quantum #:
-magnetic quantum # (ml)
-gives orientation and angular momentum
-range: negative l value TO the positive l value
4th quantum #:
-spin magnetic quantum # (ms)
-gives spin state of electron (either "spin up" or "spin down"
-range: only -1/2 or +1/2

RitaThomas_3G
Posts: 55
Joined: Wed Sep 30, 2020 9:40 pm

### Re: Quantum Numbers

s - subshell: 1 orbital
p - subshell: 3 orbitals
d - subshell: 5 orbitals
f - subshell: 7 orbitals

n = 1 shell: 1 orbital (s subshell)
n = 2 shell: 4 orbitals (s and p subshells)
n = 3 shell: 9 orbitals (s, p, and d subshells)
n = 4 shell: 16 orbitals (s, p, d, and f sub shells)