Lead, chemical element, symbol Pb; for physical constants see Periodic Table. Lead was known and used by the ancients. It is sometimes found native and occurs in the minerals anglesite, cerussite, mimetite, and pyromorphite. It is obtained by roasting its most common ore, galena, a sulfide, to its oxide and reducing with carbon in a blast furnace. Lead is a silvery, soft, heavy, metal. It is a poor conductor of heat and electricity. The metal has long been used in the lead-chamber process for the production of sulfuric acid. In the decay of uranium, thorium and actinium, a different stable isotope of lead is the end product. Lead and its compounds are used in storage batteries, X-ray shielding, cable sheathing, insecticides, detonators, solders, shot, and type metal.