Ionization potential is lowest for

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 first ionization enthalpies of $Li$,$Be$,and $C$ are $520$,$899$,and $1086 \ kJ \ mol^{-1}$ respectively. Which of the values $800$ or $900 \ kJ \ mol^{-1}$ is more likely for the first ionization enthalpy of $B$? Why?

Which of the following sets has the highest sum of $IE$ values compared to all other sets mentioned?

The first ionisation potential of $Na$ is $5.1 \, eV$. The value of electron gain enthalpy of $Na^{+}$ will be : ............... $eV$

Consider the elements $Mg$,$Al$,$S$,$P$ and $Si$. The correct increasing order of their first ionization enthalpy is: