If its a matter of FINDING it, just look on a site like www.wewbelements.com. If you mean you want to know how to do it, for the simpler elements, follow the rules that there are 2 s electrons, 6 p electrons, 10 d electrons and 14 f electrons. The order of filling is 1s2, 2s2, 2p6, 3s2 3p6 4s2, 3d10, 4p6. This will get you through element # 35 (Kr) with only two errors. Those errors are at Cr (#24), and Cu(#29). Both Cr and Cu have an extra electron in 3d and 1 fewer in 4s.
