Question

State whether the statement is True or False:

Across a period there is an increase in electron affinity (EA) value and oxidizing capacity but both properties decrease down the group.

Answer 1

As the size of the elements decreases in a period, the effective nuclear charge on the valence electron increases and this results in an increase in electronegativity. An increasing electronegativity increases the tendency of atoms to accept electrons i.e. electron affinity (EA) and thus the element itself get reduce and act as oxidizing agent.

Hence, an increase in EA value in a period increases the oxidizing ability/capacity of elements.

Similarly, the electronegativity decreases down the group, thereby decreases the electron affinity down the group i.e. reduces the electron acceptance tendency (EA) and also the oxidizing ability/capacity of elements.

Hence in a group, EA decreases downward and reduces the oxidizing capacity.