S1.3 Electron configuration
This section uses the evidence from emission spectra to explain how electrons are configured in energy levels around an atom. Each main energy level can hold a maximum of 2n2 electrons and is divided into sub-levels, s, p, d and f. Each sub-level contains a fixed number of orbitals and each orbital can hold a maximum of two electrons. From this the electron configuration of the gaseous ground state of each element...