Which of the following bond types is normally the weakest?

A) sigma bond formed by the overlap of two porbitals

B) sigma bond formed by the overlap of two sorbitals

C) pi bond formed by the overlap of two porbitals

D) sigma bond formed by the overlap of one sand one porbital

Here we have to choose the weakest bond among the given pi and sigma bonds.

The weakest bond among the given options are pi bond formed by the overlap of two p-orbitals.

We know the strength of the covalent bond is approximately proportional to the extent of overlap between the combining orbitals. Greater overlap makes a bond stronger.

There are two types of overlap one is direct overlap and lateral overlap. The direct overlap generates sigma bond whereas the lateral overlap generates pi bonds.

In the direct overlap there are more overlap than the lateral overlap thus any type of sigma bond will be more stronger than the pi bond.

Thus the weakest bond among the given options are pi bond formed by the overlap of two p-orbitals.