The order of ionisation potential between $He^{+}$ ion and $H$ atom (both species are in gaseous state) is

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

The successive ionization energy values for an element $X$ are given below:
$(i)$ $1^{st}$ ionization energy $= 410 \ kJ \ mol^{-1}$
$(ii)$ $2^{nd}$ ionization energy $= 820 \ kJ \ mol^{-1}$
$(iii)$ $3^{rd}$ ionization energy $= 1100 \ kJ \ mol^{-1}$
$(iv)$ $4^{th}$ ionization energy $= 1500 \ kJ \ mol^{-1}$
$(v)$ $5^{th}$ ionization energy $= 3200 \ kJ \ mol^{-1}$
Find the number of valence electrons in the atom $X$.

Which of the following orders for ionization energy is correct?

The correct order of second ionization potential of carbon,nitrogen,oxygen and fluorine is

The ionization potentials of $Li$ and $K$ are $5.4 \ eV$ and $4.3 \ eV$ respectively. The ionization potential of $Na$ will be .............. $eV$.