Question

How many species of the following would involve sp mixing?
$B_2,O_2,F_2,N_2,O_2^{+},F_2^{-},C_2,O_2^{-}$

Answer 1

Answer: 3

$\left(B_2,N_2,C_2\right)$
Homodiatomic species up to nitrogen show $s-p$ mixing due to less energy difference between $2s$ and $2p$ orbitals.