Bond dissociation energy of E-H bond of the HE hydrides of group 16 elements follows order:

(A) O
(B) S
(C) Se
(D) Te

Question

Bond dissociation energy of E-H bond of the HE hydrides of group 16 elements follows order:

(A) O
(B) S
(C) Se
(D) Te

Canvas Classes · Accepted Answer

Strategy:
 Bond energy depends on the strength of orbital overlap, which is highest when the atomic sizes of the bonded atoms are more compatible. As the central atom () size increases down a group, the bond length () increases and strength decreases.

Step 1: Compare Group 16 hydrides
Group 16 elements: .
Atomic size: .
Bond length:  (shortest)   (longest).

Step 2: Order Bond Dissociation Energy (BDE)
Longer bonds are easier to break. Therefore, BDE decreases down the group.
Order: .

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