Question

The correct order of electron gain enthalpy is :-

• A. S > Se > Te > O
• B. O > S > Se > Te
• C. Te > Se > S > O
• D. S > O > Se > Te

Answer 1

The correct option is A

S > Se > Te > O

The correct answer is option A.

Explanation of correct answer :-

• Electron gain enthalpy is the amount of energy released when an extra electron is added to an atom to convert it into anion.
• On moving down the group, the distance between electrons and nucleus increases causing less attraction between them.
• Consequently, Electron gain enthalpy also becomes less .
• Therefore, electron gain enthalpy of 16^th group is as follows :S > Se > Te > O
• Here, Oxygen is an exception . It has low electron gain enthalpy due to its smaller size.
• The attraction between nucleus and surrounding electron is that strong that it does not allow any electron to be added.