Question

What are the ground state and the second excited state of a beryllium atom?

Answer 1

The ground state is `1s^2 2s^2`, and I believe what you are referring to as the second excited state would be `1s^2 2p^2`

Explanation:

The ground state is `1s^2 2s^2`, but I'm not clear on the meaning of "second excited state". I will guess that we are talking about raising the energy of one of the `2s` electrons into a higher energy level.

If so, the first excited state is `1s^2 2s^1 2p^1`, I assume the second one is `1s^2 2p^2`, as this would require less energy than elevating a valence electron all the way up to `3s`.