Question

The correct sequence of electron gain enthalpy of the elements listed below is
A. Ar 
B. Br 
C. F 
D. S 
Choose the most appropriate from the options given below:

• A. C > B > D > A
• B. A > D > B > C
• C. A > B > D > C
• D. D > C > B > A

Answer 1

The Correct Option is B

Electron Gain Enthalpy Defined: Electron gain enthalpy quantifies the energy change when an electron is added to a neutral gaseous atom, forming an anion. A more negative value signifies greater energy release, indicating a higher electron affinity.

Element Analysis: We will now order Ar, Br, F, and S by their electron gain enthalpy.

• Argon (Ar): As a noble gas with a full valence shell, Argon exhibits negligible electron affinity.
• Fluorine (F): Fluorine possesses a high electron affinity due to its proximity to a complete octet, being the halogen with the strongest electron affinity.
• Bromine (Br): Bromine, another halogen, also displays high electron affinity, though less so than Fluorine. Its electron gain enthalpy is less negative than Fluorine's.
• Sulfur (S): Sulfur demonstrates a moderate electron affinity, which is less than that of halogens like Bromine and Fluorine.

Electron Gain Enthalpy Ranking: Based on the preceding analysis, the elements are ordered from the most negative electron gain enthalpy (greatest energy release) to the least:

• Argon has the least negative electron gain enthalpy due to its noble gas configuration.
• Following Argon, Sulfur exhibits a lower electron gain enthalpy than Bromine.
• Bromine's electron gain enthalpy is lower than Fluorine's.
• The resultant order is: \(A \gt D \gt B \gt C\)

Final Ordering: The sequence of electron gain enthalpy for the specified elements, from most negative to least negative, is A > D > B > C.