The energy of an electron in the ground state ( n =1) for He^+ ion is -xJ, then that for an electron in n =2 state for Be^3+ ion in J is:

The energy of an electron in the ground state $\displaystyle (\mathrm{n}=1)$ for $\displaystyle \mathrm{He}^{+}$ion is -xJ , then that for an electron in $\displaystyle \mathrm{n}=2$ state for $\displaystyle \mathrm{Be}^{3+}$ ion in J is :