# Question #b71e0

3

#### Explanation:

The electron configuration of boron is $1 {s}^{2} 2 {s}^{2} 2 {s}^{1}$

Valence electrons are the ones in the highest energy levels. For boron this would be the 2 electrons in the 2s sublevel and the 1 electron in the 2p sublevel.

The videos below might be helpful for this concept.

Hope this helps!