Answer
$\sigma$ bonds are formed by the head-on overlap of hybrid orbitals along the internuclear axis, while $\pi$ bonds are formed by the side-to-side overlap of unhybridized p orbitals perpendicular to the internuclear axis.
Work Step by Step
In the hybrid orbital model, the $\sigma$ bonds and $\pi$ bonds have the following differences:
1. Orbital Overlap:
- $\sigma$ bonds are formed by the head-on overlap of atomic orbitals along the internuclear axis (z-axis).
- $\pi$ bonds are formed by the side-to-side overlap of atomic orbitals perpendicular to the internuclear axis (x- and y-axes).
2. Directionality:
- $\sigma$ bonds have a higher degree of directionality and are stronger than $\pi$ bonds.
- $\pi$ bonds have a lower degree of directionality and are weaker than $\sigma$ bonds.
3. Orbital Contributions:
- $\sigma$ bonds are formed by the overlap of hybrid orbitals, such as sp, sp², or sp³ orbitals.
- $\pi$ bonds are formed by the overlap of unhybridized p orbitals.
Specifically, in the hybrid orbital model:
1. $\sigma$ Bonds:
- The $\sigma$ bonds are formed by the head-on overlap of hybrid orbitals (sp, sp², or sp³) along the internuclear axis (z-axis).
2. $\pi$ Bonds:
- The $\pi$ bonds are formed by the side-to-side overlap of unhybridized p orbitals perpendicular to the internuclear axis (x- and y-axes).
