Question #f8cff

1 Answer
Apr 14, 2016

The #4s# subshell has a lower energy level compared to the #3d# because it is closer to the nucleus.

Explanation:

The #4s# subshell is overlapped by the #3d# subshell so it is closer to the nucleus.

Imagine the nucleus as your body. The #4s# subshell would be your t-shirt, and the 3d subshell would be your shirt. The
3d is further away from your body so it has a higher energy level.

THE key point is:

The further away a subshell is, the more energy the electrons need to have in order to stay within it's region.