lead (Pb), a soft, silvery white or grayish metal in Group 14 (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.
Lead is a neurotoxin that accumulates in soft tissues and bones; it damages the nervous system and interferes with the function of biological enzymes, causing neurological disorders ranging from behavioral problems to brain damage, and also affects general health, cardiovascular, and renal systems. Contents 1 Physical properties 1.1 Atomic 1.2 Bulk
as in to command. to serve as leader of a senior programmer is leading the team that is developing the new accounting software. Synonyms & Similar Words. command. captain. spearhead. head. direct. oversee.
Lead, a metal found throughout the earth, has been used in a variety of products including gasoline, paint, plumbing pipes, ceramics, solders, batteries, and even cosmetics. It remains a significant public health concern for some children because of persistent lead hazards in the environment.
Jan 21, 2022 · Lead is a metal that occurs naturally in the earth's crust, but human activity — mining, burning fossil fuels and manufacturing — has caused it to become more widespread. Lead was also once used in paint and gasoline and is still used in batteries, solder, pipes, pottery, roofing materials and some cosmetics. Lead in paint
Aug 31, 2022 · Lead is a cumulative toxicant that affects multiple body systems and is particularly harmful to young children. Lead in the body is distributed to the brain, liver, kidney and bones. It is stored in the teeth and bones, where it accumulates over time. Human exposure is usually assessed through the measurement of lead in blood.
1. To show the way to by going in advance: The host led us to our table. See Synonyms at guide. 2. To guide or direct in a course: lead a horse by the halter. 3. a. To serve as a route for; take: The path led them to a cemetery. b. To be a channel or conduit for (water or electricity, for example). 4.