Question

Ongoing from c to n in the second period, the values of electron affinity decreases instead of increasing.

Answer 1

Electron affinity is the energy released when one mole of an electron is added to a gaseous atom to form one mole of gaseous ion.

On moving across the period from C to N the atomic size increases the nuclear force of attraction decreases leading to the decrease in the electron affinity as force needed to attract an electron becomes less.

Answer 2

Electron affinity: The energy released when an electron is added to a neutral atom or molecule is referred to as electron affinity.

The reaction is exothermic.

The atoms in the gaseous state form a negative ion when energy is released.

The energy is positive.

On moving across the periodic table, the electron affinity increases.

But, the period from Carbon to Nitrogen experience an adverse reaction.

Reason:

• The electron affinity decreases because the atomic size increases.
• The nuclear force of attraction decreases
• The attraction for an electron becomes less.

Hence, Ongoing from c to n in the second period, the values of electron affinity decreases instead of increasing.