# What is the electron configuration of a selenium atom in an excited state?

##### 1 Answer
Jun 15, 2017

$\text{[Ar]3d"^10"4s"^2"4p"^3"5s"^1}$

#### Explanation:

The excited state of an atom occurs when it has absorbed energy. When this happens, an electron can jump to a higher energy level, which is very unstable, before dropping back to its ground state.

Ground state electron configuration for selenium, atomic number $34$ is:

$\text{[Ar]3d"^10"4s"^2"4p"^4}$

An excited state electron configuration could be:

$\text{[Ar]3d"^10"4s"^2"4p"^3"5s"^1}$

One $\text{4p}$ electron is now occupying the $\text{5s}$ orbital.