Apart from the magical process of s-p mixing, another magical process happens during the formation of molecular orbitals – sp-hybridisation!

To summarise, there are three main types of s-p hybrids available and they are as follows:

• sp³
• sp²
• sp

The shapes and angles of the hybrid atomic orbitals formed from s-p hybridisation are summarised below.

Bond angle and shapes associates with sp, sp2 and sp3 hybridisation

Sp³ hybridisation

One s orbital and three p orbitals hybridise to form four degenerate sp³ hybrid atomic orbitals (HAOs). The HAOs point towards the corners of a tetrahedron, thus, forming tetrahedral shape upon forming molecular orbitals. The bond angle in compounds with sp³ hybridisation is 109.5^o, allowing the compound to be more stable.

One example of a sp³ hybridised compound is C₂H₆.

Atomic orbitals overlap in C2H6

Sp² hybridisation

Sp² hybridised compounds are planar with a bond angle of 120^o. This is because three degenerate sp² hybrid atomic orbitals are produced.

One of the sp² hybridised compounds are CH₂O.

Atomic orbitals overlap in CH2O

Sp hybridisation

Sp hybridised compounds are also planar, with a bond angle of 180^o that will keep bond pairs as far away from each as possible.

An example of a sp hybridised compound is a C₂H₂.

Atomic orbitals overlap in C2H2