The total number of molecular orbitals formed from 2s and 2p atomic...

2s and 2p atomic orbitals combine, forming σ (sigma) and π (pi) molecular orbitals. σ orbitals result from head-on overlap, while π orbitals arise from sideways overlap. This molecular orbital theory explains the bonding in molecules

 $2s$ orbital will form, two molecular orbitals $\sigma2s$ and $\sigma * 2s$.
$2p$ orbital will form six molecular orbitals $\sigma2{p}_{z}$ and $\sigma * 2{p}_{z}$. $\pi2{p}_{x}, \pi2{p}_{y}$ and $\pi * 2{p}_{x}, \pi * 2{p}_{y}$

Hence the total number of molecular orbitals formed from $2s$ and $2p$ atomic orbitals of a diatomic molecule formed is $8$.