Sp, sp2, and sp3 hybridization are terms used to describe the bonding of atoms in molecules. Hybridization refers to the mixing of atomic orbitals to form new hybrid orbitals that are suitable for bonding. Here's a breakdown of each type of hybridization:

Sp Hybridization:
- In sp hybridization, one s orbital and one p orbital combine to form two sp hybrid orbitals.
- These orbitals are arranged in a linear geometry, with an angle of 180 degrees between them.
- Examples of molecules with sp hybridization include acetylene (C2H2) and hydrogen cyanide (HCN).

Sp2 Hybridization:
- In sp2 hybridization, one s orbital and two p orbitals combine to form three sp2 hybrid orbitals.
- These orbitals are arranged in a trigonal planar geometry, with an angle of 120 degrees between them.
- The remaining p orbital is left unhybridized and perpendicular to the plane of the sp2 hybrid orbitals.
- Examples of molecules with sp2 hybridization include ethene (C2H4) and formaldehyde (CH2O).

Sp3 Hybridization:
- In sp3 hybridization, one s orbital and three p orbitals combine to form four sp3 hybrid orbitals.
- These orbitals are arranged in a tetrahedral geometry, with an angle of 109.5 degrees between them.
- Examples of molecules with sp3 hybridization include methane (CH4) and ammonia (NH3).

In summary, sp, sp2, and sp3 hybridization describe the way in which atomic orbitals combine to form new hybrid orbitals that are suitable for bonding. The resulting hybrid orbitals have different geometries, which determine the shape of the molecule.

Sp hybridization occurs due to mixing of one s and one p atomic orbital,sp2 hybridization is the mixing of one s and two p atomic orbital, sp3 hybridization is the mixing of one s and three p atomic orbital.