The five successive ionisation energies of an element are $800, 2427,3658, 25024$ and $32824 \mathrm{kJ} {\mathrm{mol}}^{-1}$ respectively. The number of valence electrons is

For one of the elements various successive ionisation enthalpies (in $\mathrm{kJ} {\mathrm{mol}}^{-1}$) are given below: 

The element is

The following table shows the successive molar ionization energy ($\mathrm{kJ} {\mathrm{mol}}^{-1}$ ) of five elements A to E.

Which of two elements are most likely to be in the same group of the periodic table?