The electron configurations described in this chapter all refer to gaseous atoms in their ground states. An atom may absorb a quantum of energy and promote one of its electrons to a higher-energy orbital. When this happens, we say that the atom is in an excited state. The electron configurations of some excited atoms are given. Select the configuration that would correspond to an excited state of As.
1) 1s2 2s2 2p6 3s2 3p6 4s2 3d10 4p4
2) 1s2 2s2 2p6 3s2 3p6 4s2 3d10 4p6
3) 1s2 2s2 2p6 3s2 3p6 4s2 3d10 4p2
4) 1s2 2s2 2p6 3s2 3p6 4s2 3d10 4p5