If radiation corresponding to first line of "Balmer series" of ${\mathrm{He}}^{+}$ ion is subjected to a sample of ${\mathrm{Li}}^{+2}$ ion (containing atoms in different energy states) and it causes ejection of photoelectron with non-zero kinetic energy then calculate least shell number in  which the electron must e present in ${\mathrm{Li}}^{+2}$.