Explain sp hybridisation with an example.

Explanation

`C_(1)H_(2)`-ethyne of acetylene
Electronic configuration of C excited state `-1s^(2)2s^(2)2p^(3)`
Valance orbital representation

Sp hybridised, C contains 2 unpaired electron and one each in py and pz two sp hybridised C combines with two `1s^(1)` orbital of H.
Two more hybrid orbitals each carbon with 1 s atomic orbitals of hydrogen to form sigma bonds. The unhybrised 2pz orbitals of both the carbon atoms now overlap sideways to form carbon-carbon pi-bond.