Question

Which of the following has zero electron affinity:

• A. Oxygen
• B. Fluorine
• C. Nitrogen
• D. Neon

Answer 1

The correct option is D

Neon

Explanation for the correct answer:-

Option (D) Neon

• Neon is an inert gas, that is they have a completely filled outermost shell.
• As a result of this, they are non-reactive in nature, as they already have achieved the octet state.
• Electron affinity is the amount of energy that is released when electrons are added to a neutral atom to form an anion.
• Since Neon has a completely filled outermost shell$\left(1{\mathrm{s}}^{2}2{\mathrm{s}}^{2}2{\mathrm{p}}^6\right)$, it does not gain any electron and thus has zero electron affinity.
• Hence it is the correct option.

Explanation for the incorrect option:-

Option (A) Oxygen

• Oxygen has an electronic configuration of $1{\mathrm{s}}^{2}2{\mathrm{s}}^{2}2{\mathrm{p}}^4$and needs 2 electrons to gain octet state.
• Thus it releases energy in order to gain the electrons and thus possess electron affinity.
• Hence it is the incorrect option.

Option (B) Fluorine

• Fluorine has an electronic configuration of $1{\mathrm{s}}^{2}2{\mathrm{s}}^{2}2{\mathrm{p}}^5$and needs 1 electrons to gain octet state.
• Thus it releases energy in order to gain 1 electron and thus possess electron affinity.
• Hence it is the incorrect option.

Option (C) Nitrogen

• Nitrogen has an electronic configuration of $1{\mathrm{s}}^{2}2{\mathrm{s}}^{2}2{\mathrm{p}}^3$and needs 3 electrons to gain octet state.
• Thus it releases energy in order to gain 1 electron and thus possess electron affinity.
• Hence it is the incorrect option.

Therefore, option (D) Neon is the correct answer.