If the energy of the electron in the 1^st orbit of hydrogen is -13.6 eV, then how much is the energy (in eV) of an electron in the 3^rd orbit?

Concept-

• The atoms have protons and neutrons in the nucleous of the atom and electrons revolve around the nucleous in the orbits.
• For each orbits there is a certain amount of energy for the electrons.

The energy of electrons in any orbit is given by:

Where n is principle quantum number and Z is atomic number

CALCULATION:

For hydrogen atom:

Atomic number (Z) = 1

Given that

Energy of electron in first orbit , E0 = -16.6

Principle quantum number of 3rd orbit, n = 3