铅(lead)
金属化学元素，化学符号Pb，原子序数82。为银白色或浅灰色金属，质地柔软，延展性好，密度大，导电性差。其稳定的同位素为铀和其他重金属放射衰变後的最终产物。自古以来人们就知道铅的好处，它耐用且抗腐蚀，所以古罗马人的铅水管至今仍可使用。铅可用作屋顶材料、电缆的包皮、水管衬里和一些管道设备。其他用途有制造蓄电池、枪弹和低熔点的合金（如焊料和白鑞），以及隔离声音、振动和幅射的保护装置。铅在自然界中很少呈游离态，主要存在硫化物和方铅矿中。由於铅和铅化物具有毒性（参阅lead poisoning），因此含铅的颜料和汽油添加物现已被禁用。铅化物的原子价有+2和+4价，其中铅氧化物（密陀僧）是最广为使用的。铅化合物可用於制造铅水晶玻璃（参阅glass）、釉料、陶器、颜料、涂料和油漆的乾料、杀虫剂、除草剂、防火材料、火柴、炸药和烟火。将近一半的铅可刮下重新回收使用。铅笔中的「铅」指的是石墨。
English version：
lead
Metallic chemical element, chemical symbol Pb, atomic number 82. Lead is a soft, silvery-white or grayish, malleable, ductile, dense metal that conducts electricity poorly. Its stable isotopes are all end products of radioactive decay of uranium and other heavy elements. Known since ancient times, lead is so durable and resistant to corrosion that Roman lead pipes are still usable. Lead is used in roofing, as cable coverings, and in pipes, conduits, and structures. Other uses are in storage batteries, ammunition, and low-melting-point alloys (e.g., solder, pewter) and as shielding against sound, vibrations, and radiation. Lead is rarely found free in nature; its major ore is the sulfide, galena. Because it and its compounds are poisons (see lead poisoning), lead-based paints and gasoline additives have been banned. Lead in compounds has valence 2 and 4; an oxide (litharge) is the most widely used. Lead compounds are added to lead crystal (see glass), glazes, and ceramics and used as pigments, drying agents for paints and varnishes, insecticides and herbicides, and fireproofing agents and in matches, explosives, and pyrotechnics. Almost half of all lead is recovered from recycled scrap. The “lead” in pencils is graphite.