[K.C.P]

I drew the MO for Be2 and found a bond order of 0. The question then says but Be2 is still observed (very rarely). Propose a reason why this is.

Not sure but might it exist under some other electronic state (i.e. not the ground state configuration) if we can some how excite the molecule?

If a configuration gives a bond order of 0 is the molecule guaranteed to not exist?

Thanks.

[FeLiXe]

the idea is that the p-orbitals mix in and stabilise the HOMO