Which of the following elements will have the lowest first ionisation energy?

Which among the following orders of second $IP$ (Ionization Potential) is correct?

What will be the order of $1^{st}$ ionisation energy for the alkali metals $Li$,$Na$,and $K$?

The first,second and third ionisation energies ($E_1, E_2$ and $E_3$) for an element are $7 \ eV$,$12.5 \ eV$ and $42.5 \ eV$ respectively. The most stable oxidation state of the element will be

If $X$ and $Y$ are the second ionisation potentials of alkali and alkaline earth metals of the same period,then:

The first ionization enthalpy of $O$ is less than that of $N$,because .........