Lead

Symbol

Pb

Atomic number

82

Atomic mass	207.2		Thermal conductivity	0.353
Atomic radius	1.47		Covalent radius	1.81
Density	11.4		Atomic volume	18.17
Melting point	600.65		Oxidation states	4,2
Boiling point	2013		Stable isotopes	4
Heat of vapor.	177.7		Electronegativity	2.33
Heat of fusion	4.799		First ionization	7.416
Specific heat	0.13		Electrical conduct.	4.5

Electron configuration

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. The organic lead compound tetraethyl lead, Pb(C₂H₅)₄, was widely used as a gasoline additive to prevent knock in automobile until concern about lead toxicity caused that use to be discontinued.

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. The mineral form of lead dioxide is called Plattnerite.

White lead is a basic carbonate of lead, Pb₃(OH)₂(CO₃)₂, which was widely used as a white pigment in paint until concerns about lead toxicity brought a halt to most such uses. Lead carbonate, PbCO₃, in mineral form is called cerussite. Lead chromate, PbCrO₄, is also used as a pigment under the name chrome yellow. A brilliant red-orange color is exhibited by the mineral crocoite, a mineral form of PbCrO₄.

Lead in its metallic form is widely used for radiation shielding because of its high absorption constant for x-rays and gamma-rays.

Lead occurs naturally in the sulfide mineral galena (PbS) and occurs with vanadium in vanadinite. A carbonate form of lead is phosgenite. Lead sulfate, PbSO₄, in the mineral form anglesite is sometimes of gem quality. Lead forms an oxide mineral with titanium, iron and manganese called senaite. Lead forms a sulfide with antimony and iron called Jamesonite and sulfides with antimony called zinkenite, plagionite, semseyite and boulangerite. Dufrenoysite and gratonite are sulfides of lead with arsenic. A sulfide formed with antimony and arsenic is called jordanite. A sulfide formed with tin, iron and antimony is called cylindrite. Bournonite is a sulfide with copper, lead and antimony. Lead is found in the mineral nagyagite, a sulfide, along with gold, iron, antimony, and tellurium. Silver joins with lead and antimony in the sulfide andorite, AgPbSb₃S₆. Lead, copper and iron join in the sulfide betekhtinite. In the sulfide mineral hutchinsonite,(Tl, Pb)₂As₅S₉ , lead joins with arsenic and thallium. One mineral form of selenium is the compound with lead, clausthalite, PbSe.

Beudantite is a mineral containing iron and lead along with sulfate and arsenate groups, PbFe₃(AsO₄,SO₄)₂(OH)₆. A striking green color is exhibited by the mineral bayldonite which combines copper, zinc and lead with an arsenate group. The phosphate mineral pyromorphite , Pb₅(PO₄)₃Cl, also exhibits a green color although it also appears in browns, reds and yellows.

Lead is one of the few elements which can be found in nature in pure form. This sample of lead with pyrochroite is displayed in the Smithsonian Museum of Natural History. The large sample is about 18x30 cm and is from Langban Mine, Filipstad, Varmland, Sweden.

Lead Nuclear Data