text: sp3, sp2, sp notation for c? stuck again, im trying to work out why a carbon bonded to four atoms has an sp3 notation for c, a carbon bonded to three atoms has an sp2 notation for c, and a carbon bonded to two atoms has an sp notation?  im pretty sure its something to do with the hybridisation theory a carbon atom forms four bonds. in its outer shell it has 1 s orbital and 3 p orbitals.  when it forms a single bond, 3 p orbitals are combned with 1 s orbital - sp3 when it forms a double bond, 2 p orbitals are combiined with 1 s orbital - sp2 when it forms a triple bond, 1 p orbital is combined with 1 s orbital - sp