Question

When 2s orbital overlaps with `2p_(x)` or `2p_(y)` orbital (assuming Z -axis as the internuclear axis) threr is a partical overlap and they do not form any `MO` Explain why ? .

Answer 1

2s orbital function has same sign throughout but `2p_(x)` or `2p_(y)` orbital wave function has + ve sing in one lobe and -ve sign in the other lobe The small (+)(+) overlap cancels the (+)(-) overlap which being equal in area but opposite in sign .