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black lead

(Encyclopedia) black lead: see graphite.

Leading U.S. Mining State

The Question: Which U.S. state produces the most coal? The Answer: When it comes to coal mining in the United States, Wyoming leads the way. The Cowboy…

lead, chemical element

(Encyclopedia) lead, metallic chemical element; symbol Pb [Lat. plumbum]; at. no. 82; at. wt. 207.2; m.p. 327.502℃; b.p. about 1,740℃; sp. gr. 11.35 at 20℃; valence +2 or +4. One of the oldest metals…