# What is the number of valence electrons found in an atom of a Group A element equal to?

The electron configuration of Lithium is $1 {s}^{2} 2 {s}^{1}$
The electron configuration of Sodium is $1 {s}^{2} 2 {s}^{2} 2 {p}^{6} 3 {s}^{1}$