NCERT Exercise 4.35 - Chemical Bonding and Molecular Structure

Question: Use MO theory to explain why Be2 does not exist.

Answer: Be2 has (sigma2s)2(sigma*2s)2, so bond order = (2 - 2)/2 = 0. There is no net bond and Be2 is not stable.

Full step-by-step NCERT solution with diagrams on Something by Zero.