lithium science definition

A soft, silvery metallic element of the alkali group that occurs in small amounts in some minerals. It is the lightest of all metals and is highly reactive. Lithium is used to make alloys, batteries, glass for large telescopes, and ceramics. Atomic number 3; atomic weight 6.941; melting point 179°C; boiling point 1,317°C; specific gravity 0.534; valence 1. See Periodic Table.