Question

Which atomic orbitals are more likely to mix to form a set of molecular orbitals: a 2s and a 3p orbital or a 4s and a 5p orbital?

Answer 1

2s and a 3p are closer than 4s and 5s,sothis atomic orbitals are more likely to mix to form a set of molecular
orbitals, while between 4s and 5s there are more orbitals (4p, 4d).