Which of the following elements has the highest metallic character?
Element $- IP$

The first ionisation potential $(IP)$ of the elements $Na$,$Mg$,$Si$,$P$,$Cl$ and $Ar$ are $5.14$,$7.65$,$8.15$,$10.49$,$12.97$ and $15.76 \ eV$,respectively. The $IP$ (in $eV$) of $K$ is closest to

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

For the second period elements,the correct increasing order of first ionisation enthalpy is:

Which one of the following orders is correct for the first ionisation energies of the elements?

How would you explain the fact that the first ionization enthalpy of sodium is lower than that of magnesium but its second ionization enthalpy is higher than that of magnesium?