Electron configurations come in several varieties: Bohr notation; sublevel notation; and orbital notation. This PowerPoint show explains the energy considerations for electron placement and develops a model to determine the order of filling. This information is used to draw the sublevel notation. The sublevel notation is used to derive both the Bohr notation and the orbital notation.
Support materials and worksheets are available free of charge on my web site at www.evanschemistrycorner.com