CHEMISTRY GUIDE

This page describes the reactions of the Period 3 elements from sodium to argon with water, oxygen and chlorine. Reactions with water Sodium Sodium has a very exothermic reaction with cold water producing hydrogen and a colourless solution of sodium hydroxide. Magnesium Magnesium has a very slight reaction with cold water, but burns in steam. A very clean coil of magnesium dropped into cold water eventually gets covered in small bubbles of hydrogen which float it to the surface. Magnesium hydroxide is formed as a very thin layer on the magnesium and this tends to stop the reaction. Magnesium burns in steam with its typical white flame to produce white magnesium oxide and hydrogen. Note:   If you are heating the magnesium in a glass tube, the magnesium also reacts with the glass. That leaves dark grey products (including silicon and perhaps boron from the glass) as well as the white magnesium oxide. Not...