Question

Which of the following bonds is most stable?

• A. 1 s-1 s
• B. 2 p-2 p
• C. 2 s-2 p
• D. 1 s-2 p

Answer 1

The correct option is A 1 s-1 s

1. The bond strength or bond stability depends on extent of overlap, higher the overlap, higher will be the bond stability.

2. The extent of overlap decreases with the increasing size of the atomic orbitals whether it is head-on(sigma bond) or lateral overlap(pi bond).

3. The extent of overlap will be greater between the overlap between two similar atomic orbitals. $s-s$ orbital overlap will be more efficient than the $s-p$ orbital overlap.

4. $s-s$ orbital overlap is more efficient than the $p-p$ orbital overlap(due to the spherical size of s orbital).

Considering all the above facts, it is clear that the $1s-1s$ bond will be the most stable one.