Of the following isoelectronic ions,the one which has the lowest ionisation potential is

The first ionization potentials $\left( eV \right)$ of $Be$ and $B$ respectively are:

Generally,the first ionization energy increases along a period. But there are some exceptions. One which is not an exception is

The first ionization energy of boron is less than that of beryllium because

First and second ionization enthalpies of lithium are $520 \text{ kJ mol}^{-1}$ and $7297 \text{ kJ mol}^{-1}$ respectively. Energy required to convert $3.5 \text{ mg}$ lithium $(g)$ into $Li^{2+}(g)$ [$Li(g) \rightarrow Li^{2+}(g)$] is . . . . . . $\text{kJ}$. (nearest integer) [Molar mass of $Li = 7 \text{ g mol}^{-1}$]

The correct order of the first ionization enthalpy is