# Question #8926c

Sep 3, 2017

${.}^{\text{16}} O$

#### Explanation:

The definition of quantum spin is $\text{+/-} \left(\frac{1}{2}\right)$. A fractional quantum spin thus can only exist when there are unpaired electrons.

The only element of the selection that has paired electrons in its valence shell is Oxygen-16, with an electron configuration of
$1 {s}^{2} 2 {s}^{2} 2 {p}^{4}$

All of the others have an uneven number of valence electrons, and therefore an unpaired electron.