If ionization potential for hydrogen atom is 13.6eV, then ionization potential for He⁺ will be

Options

(a) 54.4 eV
(b) 6.8 eV
(c) 13.6 eV
(d) 24.5 eV

Correct Answer:

54.4 eV

Explanation:

The ionization energy of any hydrogen like species (having one electron only) is given by the equation I.E = (2π²Z²me⁴)/h². Since the atomic number of H is 1 and that of He is 2, therefore,the I.E. of He⁺ is four times = Z²=(2²) the I.E. of H. So, 13.6 x 4= 54.4 eV