## 7th edition 1D.25

Alyssa Bryan 3F
Posts: 61
Joined: Fri Sep 28, 2018 12:26 am
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### 7th edition 1D.25

Can someone explain the reason the 2d and 4g subshells cannot exist in an atom?

Anusha 1H
Posts: 65
Joined: Fri Sep 28, 2018 12:15 am

### Re: 7th edition 1D.25

Both 2d and 4g don't satisfy the requirements for the angular momentum quantum numbers (or l).

l can only have the values 0,1,....n-1
In the case of 2d, n=2. This means l can either be 0 or 1. These 2 numbers are l values for s-orbitals and p-orbitals.
Because l cannot be equal to 2, it cannot have a d-orbital

The same idea applies to 4g.
When n=4, l can be equal to 0,1,2, or 3 (s, p, d, or f-orbitals).
The size cannot have a g orbital

Jake Gordon 1A
Posts: 61
Joined: Fri Sep 28, 2018 12:15 am

### Re: 7th edition 1D.25

The 2d and 4g subshells can not exist for the following reasons

The d sub shell requires the angular momentum quantum number to be two. The highest value this number can be is the energy level (2 in this case) minus one. Therefore 2d is impossible

4g can not exist for the same reason: g requires the "l" angular momentum number to be 4 because 0=s 1=p 2=d 3=f 4=g
The energy level is 4 making the highest possible "l" 3 which is too low for a g sub shell