If you look on the main website, under each element name, it'll tell you there :)

eg. for Ca: http://www.webelements.com/webelements/elements/text/Ca/econ.html

Note, where it says [Ar], you'll need to replace that with the electronic configuration of Ar (1s^2 2s^2 2p^6 3s^2 3p^6)