hybridisation

sp3

all 4 orbitals are hybridised

the 2 orbitals are in between and never on the axis and combine into a tetrahedral structure

used when you have 4 separate bonds

sp2

3 hybridised orbitals, 1 unhybridized

associated with double bonding as 2 different types of bonds (sigma and pi) are formed with different overlaps, and this does not require the same level of hybridisation. the unhybridized orbital forms the pi bond in the double bond

associated with trigonal planar shape

arises when you have a double bond and 2 single

sp

2 hybridised orbitals, 2 unhybridized

occurs when you either have 2 double bonds or a single and a triple bond. this means 2 pi bonds are required, formed by the 2 unhybridized orbitals

associated with linear shape

hybridisation

hybridisation is a mixing of atomic orbitals used to produce hybrid orbitals used in bonding

the electron in the 2s orbital is excited and occupies a vacant 2p orbital. the orbitals then become degenerate (have the same energy)/hybridise with the 2s orbital. the total energy stays the same, but the energy of each orbital is in between 2s and 2p

hybridized orbitals change shape, unhybridized retain their shape

lone pairs of electrons can exist in hybrid orbitals and contribute towards the shape (done according to edg)