What one is it?

if two electrons have the same n, the same ℓ, and the same ml, then they are in the same orbital. the pauli exclusion principle states that no two identical fermions (a fancy word for electrons and other subatomic particles like electrons) may occupy the same quantum state in an atom simultaneously.

- both b and d.

-since b and d are the closest coastlines then that makes it the most affected.

< 3

1 a

2 d

3 a

4 c

explanation: