Question

# The decreasing order of the second ionization potential of K, Ca and Ba is:(A) K > Ca > Ba(B) Ca > Ba > K(C) Ba > K > Ca(D) K > Ba > Ca

Hint: In order to solve this question electronic configuration of K, Ca and Ba should be considered. The second ionization energy refers to the energy required to remove an electron after an electron has already been removed from the isolated gaseous atom.

- Electronic configuration of Potassium: $\left[ {Ar} \right]4{s^1}$
- Electronic configuration of Calcium: $\left[ {Ar} \right]4{s^2}$
- Electronic configuration of Barium: $\left[ {Xe} \right]6{s^2}$