Consider the following ionization enthalpies of two elements 'A' and 'B'

Which of the following statements is correct ?

Options

A. Both 'A' and 'B' belong to group -1 where 'B' comes below 'A'.
B. Both 'A' and 'B' belong to group -1 where 'A' comes below 'B'.
C. Both 'A' and 'B' belong to group -2 where 'B' comes below 'A'.
D. Both 'A' and 'B' belong to group -2 where 'A' comes below 'B'.

Answer

C

Explanation

Generally, the ionization enthalpies or energy increases from left to right in a period and decreases from top to bottom in a group. Several factor such as atomic radius, nuclear,charge, shielding effect are responsible for change of ionization enthalpies.
Here, 1st ionization enthalpy of A and B is greater than group I(Li 520 `kJmol^(-1)` to Cs374`kJmol^(-1)`), which means element A and B belong to group -2 and all three given ionization enthalpy values are less for element B means B will come below A