Question

Same orbitas are there but how energy gap between orbitals differs in 2 cases??​

Answer 1

Explanation:

Considering that you have read the Bohr's model of an atom.... the energy difference between 2 successive orbitals differ for different elements.

The energy level of an orbital is given by  -> -13.6 * z^2/n^2

where z is the atomic number.

So using the above explanation one can say that the energy difference in Molecular Orbitals will also differ for different elements.

There is your explanation :)