lead

Name lead
Symbol Pb
Atomic Weight 207.2
Atomic Number 82
CAS ID 7439-92-1
Group Number 14
Group Name (none)
Period Number 6
Origin of Name Anglo-Saxon, lead; Latin plumbum.
Year Discovered Prehistoric.
Discovery Credits Known to ancient civilizations.
Class Metallic
Color Bluish White
Standard State Solid at 77 F & 298 K
Description Soft, weak, ductile, dull gray metal. Tarnishes in moist air but stable to oxygen and water, dissolves in nitric acid. Used in batteries, cables, paints, glass, solder, petrol, radiation shielding, etc.

Diagnostic tests:
With soda (Na2CO3) on charcoal a malleable globule of metallic lead is obtained from lead compounds, the coating has a yellow color near the assay, the sulfide gives also a white coating (PbSO3) further away.
Mixed with potassium iodide and heated on a plaster tablet, lead iodide forms a chrome-yellow sublimate.
In solution, lead, along with mercury (Hg1+) and silver form white, insoluble chlorides from aqueous solutions.

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