The ionization energies of $\text{Li}$ and $\text{Na}$ are $\text{520}\text{kJ}$ $\mathrm{m}\mathrm{o}{\mathrm{l}}^{-1}$ and $\text{495}\text{kJ}{\text{mol}}^{-1}$ respectively. The energy required to convert all the atoms present in $\text{7}\text{mg}$ of $\text{Li}$ vapours and $\text{23}\text{mg}$ of sodium vapours to their respective gaseous cations respectively are: