Symbol

Li

Atomic Number

3

Atomic Mass

6.941

Family

Group 1 (Ia) Alkali Metal Pronunciation

LI-thee-um

Overview

Lithium is the first member of the alkali metal family. The alkali metals are the elements that make up Group 1 (IA) of the periodic table. The periodic table is a chart that shows how chemical elements are related to one another. The alkali metals include sodium, potassium, rubidium, cesium, and francium. Lithium is also the least dense of all metals. It has a density about half that of water.

Credit for the discovery of lithium usually goes to Swedish chemist Johan August Arfwedson (or Arfvedson; 1792-1841). Arfwedson found the new element in a mineral that had first been identified about twenty years earlier by Brazilian scientist Joze Bonifacio de Andrada e Silva (1763-1838). That mineral, petalite, is still a major source of lithium today.

Lithium has a number of important and interesting uses. In...