Hydrogen atom has only one electron, so mutual repulsion between electrons is absent. However, in multielectron atoms mutual repulsion between the electrons is significant. How does this affect the energy of an electron in the orbitals of the same principal quantum number in multielectron atoms ?

Explanation

The energy of electron is determined by the value of n in hydrogen atom and by n + I in multielectron atom. So for a given principal quantum number electrons of s, p, d and f orbitals have different energy.