Oxidation states 4,2 Boiling point 2013 Stable isotopes 4 Heat of vapor. Back Lead Lead is a soft, heavy, dull gray metal with low tensile strength. It is used in making type, for covering electrical cables, and in many alloys. Lead forms a thin surface layer of oxide in air, which slowly changes to a basic carbonate. Hard water forms a similar coating on lead, which protects the water from further contamination with soluble lead compounds.
Soft water dissolves appreciable amounts of lead, which is poisonous.
Lead monoxide, PbO, called litharge is made by heating lead in air. It is a yellow powder or yellowish-red crystalline material which is used in making lead glass. Red lead, Pb3O4, can be made by heating lead in oxygen. It is used in glass making and for making a red paint for protecting iron and steel structures. Lead dioxide, PbO2, is widely used in lead storage batteries.