Second Ionization potential of Li, Be, B is in the order:

The correct order for second Ionization potential of Li, Be, B is $\begin{array}{r}\mathrm{Li}>\mathrm{B}>\mathrm{Be}\end{array}$

Based on the electron ejection from ${\mathrm{Li}}^{+},{\mathrm{Be}}^{+}$ and ${\mathrm{B}}^{+}$the second ionization potential is determined.

These ions have the following electronic configuration:

 $\begin{array}{l}{\mathrm{Li}}^{+}:1{\mathrm{s}}^2\\ {\mathrm{Be}}^{+}:1{\mathrm{s}}^{2}2{\mathrm{s}}^1\\ {\mathrm{B}}^{+}:1{\mathrm{s}}^{2}2{\mathrm{s}}^2\end{array}$

For lithium and boron, an electron must be expelled from stable shells that are completely filled. Furthermore, the 1s shell of Li is harder to extract an electron from since it is nearer the nucleus than the 2s shell of Boron.

Beryllium will achieve a stable electrical configuration after losing this electron, making its removal considerably simpler.

Hence,the correct order for second Ionization potential of Li, Be, B is $\begin{array}{r}\mathrm{Li}>\mathrm{B}>\mathrm{Be}\end{array}$