## 1D.21

Christine Honda 2I
Posts: 116
Joined: Sat Sep 14, 2019 12:17 am

### 1D.21

1D.21 Write the subshell notation (3d, for instance) and the num- ber of orbitals having the following quantum numbers: (a) n=5, l=2;(b)n=1,l=0;(c)n=6,l=3;(d)n=2,l=1.

Hi, I thought I understood quantum numbers but I'm not exactly sure what this problem is asking so an explanation would be great.

Julie_Reyes1B
Posts: 105
Joined: Sat Jul 20, 2019 12:16 am

### Re: 1D.21

Hi! The problem is asking you to identify a specific subshell based on the principal quantum number and angular momentum quantum number. So for (a),for example, n=5 tells us we are in the fifth shell. l=2 then indicates the subshell is "d" (l=0 is s, l=1 is p, etc). So the answer would be 5d. Within 5d (or any d subshell), there are 5 orbitals which each can hold up to two electrons.
Hope this helps!

Justin Vayakone 1C
Posts: 110
Joined: Sat Sep 07, 2019 12:19 am

### Re: 1D.21

The question is asking for a specific subshell. When we are given an n and l value, we will have a subshell. For part a) since n=5 and l=2, we know the subshell is 5d. Subshell notation is simply just the n value followed by s, p, d, or f subshells. l=0 is the s-subshell, l=1 is the p-subshell, l=2 is d-subshell, and l=3 is f-subshell. ml value indicates how many orbitals there are. You can determine an ml value through multiplying the value of l with 2 and adding 1 (or simply memorizing that s-subshell has 1 orbital, p-subshell has 3 orbitals, d-subshell 5 orbitals, and f-subshell 7 orbitals. Since part a is 5d, that means it has 5 orbitals. For part b) the answer would be 1s and only one orbital. Part c) 6f and seven orbitals. Part d) 2p and three orbitals.

Myka G 1l
Posts: 100
Joined: Fri Aug 30, 2019 12:17 am

### Re: 1D.21

This question is asking which subshell the electron belongs to based on the first two quantum numbers. For example in part a where n=5 and l=2, the sub shell is 5d. the second part of the question is asking how many orbitals could share those first two quantum numbers.

Elizabeth Harty 1A
Posts: 125
Joined: Sat Jul 20, 2019 12:16 am

### Re: 1D.21

I understand the principal quantum number part, but how does the L value help?

Julie_Reyes1B
Posts: 105
Joined: Sat Jul 20, 2019 12:16 am

### Re: 1D.21

Hi again! Without the l value, we would not know which subshell we are talking about within the shell. So n=5 tells us we are at the fifth shell, but we don’t know if we are in the s, p, d, or f subshell unless we have the l value.