The first ionisation potentials $(eV)$ of $Be$ and $B$ respectively are :-

An element has successive ionization enthalpies as $940 \, kJ \, mol^{-1}$ (first),$2080 \, kJ \, mol^{-1}$,$3090 \, kJ \, mol^{-1}$,$4140 \, kJ \, mol^{-1}$,$7030 \, kJ \, mol^{-1}$,$7870 \, kJ \, mol^{-1}$,$16000 \, kJ \, mol^{-1}$ and $19500 \, kJ \, mol^{-1}$. To which group of the periodic table does this element belong?

The electronic configuration with the highest ionization enthalpy is

The element having the greatest difference between its first and second ionization energies is:

Which of the following has the least ionization potential?

In which of the following arrangements is the order not correct according to the property indicated against it?