<Tr> <Td> Copper </Td> <Td> 29 </Td> <Td> (Ar) 4s 3d </Td> <Td> </Td> <Td> Silver </Td> <Td> 47 </Td> <Td> (Kr) 5s 4d </Td> <Td> </Td> <Td> Gold </Td> <Td> 79 </Td> <Td> (Xe) 6s 4f 5d </Td> <Td> </Td> <Td_colspan="3"> </Td> </Tr> <Tr> <Td> Zinc </Td> <Td> 30 </Td> <Td> (Ar) 4s 3d </Td> <Td> </Td> <Td> Cadmium </Td> <Td> 48 </Td> <Td> (Kr) 5s 4d </Td> <Td> </Td> <Td> Mercury </Td> <Td> 80 </Td> <Td> (Xe) 6s 4f 5d </Td> <Td> </Td> <Td_colspan="3"> </Td> </Tr> <P> The electron - shell configuration of elements beyond hassium has not yet been empirically verified, but they are expected to follow Madelung's rule without exceptions until element 120 . </P> <P> In molecules, the situation becomes more complex, as each molecule has a different orbital structure . The molecular orbitals are labelled according to their symmetry, rather than the atomic orbital labels used for atoms and monatomic ions: hence, the electron configuration of the dioxygen molecule, O, is written 1σ 1σ 2σ 2σ 3σ 1π 1π, or equivalently 1σ 1σ 2σ 2σ 1π 3σ 1π . The term 1π represents the two electrons in the two degenerate π * - orbitals (antibonding). From Hund's rules, these electrons have parallel spins in the ground state, and so dioxygen has a net magnetic moment (it is paramagnetic). The explanation of the paramagnetism of dioxygen was a major success for molecular orbital theory . </P>

List the subshell of m shell in order of increasing energy