Which of the following atoms has the lowest ionization potential ?

Options

A. `._8^16 O`
B. `._7^14 N`
C. `._55^133 Cs`
D. `._18^40 Ar`

Answer

C

Explanation

( c) Since the `._55^133 Cs` has larger size among the four atoms gives, thus the electrons present in the outermost orbit will be away from the nucleus and the electrostatic force experienced by electrons due to nucleus will be minimum. Therefore the energy required to liberate electron from outer will be minimum in the case of `._55^133 Cs`.