Consider hydrogen atom in an excited state of 3s1. What is the energy of its electron

Given:

Excited state electron configuration of H atom = 3s¹

To determine:

Energy of the electron in this state

Explanation:

The energy 'E' of an electron in a hydrogen atom occupying a level, 'n' is given by the formula:

En = - E₀/n²

where, E₀ is the ground state energy = 13.6 eV

n = principle quantum number i. e. n = 1,2,3 ...

Therefore,

En = - 13.6/n² eV

In this case for a 3s¹ configuration, n = 3

E = - 13.6 / (3) ² = - 1.51 eV

Ans: Energy of the electron in a 3s1 state is - 1.51 eV