It requires $68 \mathrm{eV}$ of energy to excite the electron from the second Bohr orbit to the third Bohr orbit in a particular single electron species having a nuclear charge of $+Ze$, where$Z$ is a constant and $e$ is the magnitude of the electronic charge. Figure out the value of$Z$.

(The ground state energy of hydrogen atom is $-13.6 \mathrm{eV}$)