An atom with high electronegativity has

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

Which one of the following is the correct order of the second ionisation potential of $Na$,$Ne$,$Mg$,and $Al$?

The correct order of first ionization enthalpy for the given four elements is:

The electronic configuration of elements $A, B$ and $C$ are $[He] 2s^1, [Ne] 3s^1$ and $[Ar] 4s^1$ respectively. Which one of the following orders is correct for the first ionization potentials (in $kJ \ mol^{-1}$) of $A, B$ and $C$?

Arrange $Li, Be, B$ and $C$ in decreasing order of their first ionisation enthalpies.