1. The kinetic energy of an electron in the first Bohr orbit of the hydrogen atom is 4.136 eV. Its kinetic energy in the second Bohr orbit will be:

(A) 2.068 eV (B) 8.272 eV (C) 16.544 eV (D) 33.088 eV

[JEE Mains 2018]

The answer is (B)

The kinetic energy of an electron in the nth Bohr orbit of the hydrogen atom is given by:

K = -13.6/n^2 eV

For n = 1, K = -13.6/1^2 = -13.6 eV

For n = 2, K = -13.6/2^2 = -3.4 eV

So, the kinetic energy of an electron in the second Bohr orbit will be 8.272 eV.

  1. The ionization potential of hydrogen atom is 13.6 eV. The energy required to remove an electron from the n = 2 state of the hydrogen atom is: