Question

The correct option for first ionisation Enthalpy( in KJmol^-1 ) minus one of Li Na k and Cs respectively (a) 496, 520, 419 , 374 (b) 374 ,419 , 496, 520 (c) 520, 496, 419, 374 (d) 374, 419,520, 496

Answer 1

Answer:

(c) 520, 496, 419, 37

ionization energy decreases as we move down the group.

Answer 2

Answer:

Answer is (c) 520,496,419,314

Ionization Enthalpy of elements is the amount of energy that an isolated gaseous atom requires to lose an electron in its ground state.

So as we go down the group  ,the number of shells keeps on increasing thereby decreasing the nuclear energy and thereby decreasing the ionisation enthalpy.