Question

Which of the following element has the maximum electron affinity?

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

Answer 1

The correct option is D

Chlorine

The explanation of the correct option:

D) Chlorine

• Electron affinity or electron gain enthalpy is defined as the amount of energy liberated when an electron is added to an atom. Electron affinity is simply an attraction towards an electron.
• Chlorine has the highest electron affinity in the periodic table.
• Reason: Chlorine needs only one electron to complete its octet and since Chlorine has a large size it easily accepts an incoming electron which contributes to the huge value of electron affinity.

The explanation of the incorrect options:

A) Fluorine

• A fluorine atom has an atomic number of nine and has a huge value of electron gain enthalpy or electron affinity as well. It also needs only one electron to fulfill its octet.
• But its electron affinity is lesser than that of chlorine. Because fluorine has a small size, it is hard for an incoming electron to enter. The interelectronic repulsion is present as well due to its small size.

B) Oxygen

• An oxygen atom has an atomic number of eight and it needs two electrons to complete its octet hence the intensity for electron affinity is lesser than that of chlorine and fluorine.
• Oxygen also experiences interelectronic repulsions as well because of its small size.

C) Nitrogen

• The nitrogen atom has an atomic number of seven and it needs three electrons to complete an octet.
• since the number of electrons to complete an octet is more, it has less electron affinity.

Hence, option D) Chlorine has maximum electron affinity.