This document provides a summary of key concepts for electron configuration in high school chemistry, including: 1) Electrons fill subshells according to the aufbau principle to achieve lowest energy, with Hund's rule specifying that electrons occupy each orbital singly before pairing up. 2) The four subshells are s, p, d, and f, with set numbers of orbitals and maximum electrons in each. Valence electrons are in the outermost shell. 3) Electron configuration can be written using boxes and...
