The energy required to remove an electron of a gaseous atom from its ground state is called

Explain why there is a phenomenal decrease in ionisation enthalpy from carbon to silicon.

The first ionization energy (in $kJ / mol$) of $Na, Mg, Al$ and $Si$ respectively,are

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

Which is the correct order of the first ionization potential of $N$,$O$,and $C$?

In the photoelectric effect,if the work functions of $Li$,$Na$,and $Rb$ are $2.41 \ eV$,$2.30 \ eV$,and $2.09 \ eV$ respectively,the work function of $K$ could approximately be in $eV$?