Solve this: Q.3. The ionisation energy of a hydrogen atom is 13.6 ev. The energy of the ground level in doubly ionised lithium is (1) - 28.7 ev (2) - 54.4 ev (3) - 122.4 ev (4) - 13.6 ev Share with your friends Share 5 Shyama Charan Mandal answered this Apply the formula thatI.E.=-13.6Z2eV Since for Lithium, Z=3, we get I.E. = -13.6Z2eV =-13.6(3) 2eV =-122.4 eV 9 View Full Answer