I'm struggling with the idea of hybridisation of orbitals. Let's start with sp^2 hybridisation of carbon, so for example in graphene. So C valence electrons ground state configuration is: 2s^2 2p^2 But am I right in saying that one of the 2s electrons is promoted to 2p, so that we have one electron in each of 2s, 2p_x, 2p_y and 2p_z ? Now somehow we get hybridisation between the 2s and two of the 2p orbitals. So, does this "hybridisation" occur within each carbon atom individually? Or does it occur between two different atoms? If it happens within each atom, what would happen if you brought in some other type of atoms? Would covalent bonds only be able to form between the new element atoms and the C atoms via the remaining 2p electron? Back to hybridation in general; can you get hybridisation of orbitals both within a single atom, AND between two or more atoms? With C we have one of the 2s electons moving to 2p to get hybridisation. Let's stay in the 2nd period of the periodic table; what happens with elements with higher atomic numbers like N, O and F? How can they hybridise? Any help would be greatly appreciated!