The excited state electron configuration of carbon is 1s22s12p3. Explain what will happen as the carbon atom returns to its ground state, and write the ground state electron configuration.

The ground state electron configuration of carbon is 1 s2 2s2 2p2. An excited state electron configuration of carbon is 1 s2 2s1 2p3. This is the state of carbon when it undergoes chemical bonding to form four covalent bonds, as in methane, CH4. However, the experimental evidence shows that all four bonds have the same energy, which can only be explained by the concept that the 2s and 2p orbitals hybridize to form four sp3 orbitals, each with one unpaired electron.