Question

Use molecular orbital theory to explain why $B{e}_2$ molecule does not exist.

Answer 1

$B{e}_2$ molecule has MO electronic configuration $KK\left(\sigma s{)}^2\right({\sigma }^{\ast }2s{)}^2$.

The bond order is $\frac{2-2}{2}=0$.

Zero bond order indicates that $B{e}_2$ molecule does not exists.