CHEMISTRY GUIDE

This page describes and explains the trends in atomic and physical properties of the Period 3 elements from sodium to argon. It covers ionisation energy, atomic radius, electronegativity, electrical conductivity, melting point and boiling point. These topics are covered in various places elsewhere on the site and this page simply brings everything together - with links to the original pages if you need more information about particular points. Atomic Properties Electronic structures In Period 3 of the Periodic Table, the 3s and 3p orbitals are filling with electrons. Just as a reminder, the shortened versions of the electronic structures for the eight elements are: Na [Ne] 3s 1 Mg [Ne] 3s 2 Al [Ne] 3s 2 3p x 1 Si [Ne] 3s 2 3p x 1 3p y 1 P [Ne] 3s 2 3p x 1 3p y 1 3p z 1 S ...