text: A carbon atom forms four bonds.\nIn its outer shell it has 1 s orbital and 3 p orbitals.\n\nWhen it forms a single bond, 3 p orbitals are combned with 1 s orbital - sp3\nWhen it forms a double bond, 2 p orbitals are combiined with 1 s orbital - sp2\nWhen it forms a triple bond, 1 p orbital is combined with 1 s orbital - sp