Question

The strength of sigma bonds formed by the overlapping of atomic orbitals is in the order:

• A. $s-s<s-p<p-p$
• B. $s-s<p-p<s-p$
• C. $s-p<s-s<p-p$
• D. $p-p<s-s<s-p$

Answer 1

The correct option is A $s-s<s-p<p-p$

We know, more is the extent of overlapping, stronger is the bond formed. The charge distribution in s - orbital is spherical thus it is non directional. On the other hand p - orbital has directional charge distribution. Thus, the sigma bond formed from overlapping of two p - orbitals will have greater overlapping compared to the bond formed by overlapping of s-p orbitals followed by the bond formed by the overlapping of s-s orbitals.
So, the strength of bond will also follow the same order and thus option (a) is correct.