LEAD

(Pb), a soft, silvery-white or grayish metal in Group IVa of the periodic table. Lead is very malleable, ductile, and dense and is a poor conductor of electricity. Known in antiquity and believed by the alchemists to be the oldest of metals, lead is highly durable and resistant to corrosion, as is indicated by the continuing use of lead water pipes installed by the ancient Romans. A brief treatment of lead follows. For a discussion of the properties and applications of lead, see Chemical Elements: Carbon group elements. For full treatment of lead and lead mining and refining, see Industries, Extraction and Processing: Low-melting metals.