Use molecular orbital theory to explain why the `Be_(2)` molecule does not exIst.

Explanation

E.C. of Be `= 1s^(2)" "2s^(2)`
M.O.E.C. of `Be_(2)=sigma1s^(2)" "sigma2s^(2)" "sigma^(**)2s^(2)` Bond order `=(1)/(2)(4-4)=0`
Hence, `Be_(2)` does not exits.