Question

Choose the wrong statement according to the valence bond theory:

• A. A $\sigma$-bond is stronger than a $\pi$-bond
• B. $p$-orbitals always have only sideways overlapping
• C. $s$-orbitals never form $\pi$-bonds
• D. There can be only one sigma bond between two atoms

Answer 1

The correct option is B $p$-orbitals always have only sideways overlapping

$\left(a\right)$ $\sigma$ bond is stronger than $\pi$ bond, because overlapping of atomic orbitals can take place to a greater extent during the formation of sigma bond compared to the formation of a $\pi$ bond.

$\left(b\right)$ $p$-orbitals can form $s-p,p-p$ overlapping axially also. Such bonds are called $\sigma$ bonds. $\pi$ bond is formed by sideways overlapping of $p$ - orbitals.

$\left(c\right)$ Only $p$ and $d$-orbitals can form $\pi$ bonds. $s$ - orbitals always form sigma bonds.

$\left(d\right)$ When the orbitals of an atoms undergoes head on overlapping to form a $\sigma$ bond, sharing of only two electrons are possible. For more electrons to be shared, lateral orbital overlapping takes place. So, there can be only one $\sigma$ bond between two atoms.