Question

Energy of an electron in second Bohr orbit is −3.4 eV. Calculate its kinetic energy and potential energy in third Bohr orbit.

Answer 1

Given: Energy in the second Bohr orbit (E₂) = −3.4 eV

Energy of an electron in a Bohr orbit is given by,

E_n = `(-13.6)/n^2` eV

Energy in third orbit (n = 3):

E₃ = `(-13.6)/3^2` eV

= `(-13.6)/9` eV

= −1.51 eV

In Bohr’s atom:

KE_n = −E_n

∴ KE₃ = −E₃

= −(−1.51 eV)

= 1.51 eV

In Bohr’s atom:

PE_n = 2E_n

∴ PE₃ = 2E₃

= 2 × −1.51 eV

= −3.02 eV