# If one of the 3p-orbitals is half-filled in the neutral atom, what is the identity of the atom?

Clearly, you are talking about the element, $\text{chlorine}$. How did I know this?
$1 {s}^{2} 2 {s}^{2} 2 {p}^{6} 3 {s}^{2} 3 {p}^{5}$
In the valence shell there are $3 {s}^{2}$, $3 {p}_{x}$, $3 {p}_{y}$, and $3 {p}_{z}$ orbitals. One of the $p$ orbitals is presumed to be half-filled.