Question

Use molecular orbital theory to explain why the Be₂ molecule does not exist.

Answer 1

The electronic configuration of Beryllium is.

The molecular orbital electronic configuration for Be₂ molecule can be written as:

Hence, the bond order for Be₂ is

Where,

N_b = Number of electrons in bonding orbitals

N_a = Number of electrons in anti-bonding orbitals

Bond order of Be₂ = 0

A negative or zero bond order means that the molecule is unstable. Hence, Be₂ molecule does not exist.