Lead is a chemical element in the carbon group with symbol Pb (from Latin: plumbum) and atomic number 82. Lead is a soft, malleable poor metal. It is also counted as one of the heavy metals. Metallic lead has a bluish-white color after being freshly cut, but it soon tarnishes to a dull grayish color when exposed to air. Lead has a shiny chrome-silver luster when it is melted into a liquid.
Lead is used in building construction, lead-acid batteries, bullets and shot, weights, as part of solders, pewters, fusible alloys, and as a radiation shield. Lead has the highest atomic number of all of the stable elements, although the next higher element, bismuth, has a half-life that is so long (much longer than the age of the universe) that it can be considered stable. Its four stable isotopes have 82 protons, a magic number in the nuclear shell model of atomic nuclei.
Lead, at certain contact degrees, is a poisonous substance to animals, including humans. It damages the nervous system and causes brain disorders. Excessive lead also causes blood disorders in mammals. Like the element mercury, another heavy metal, lead is a neurotoxin that accumulates both in soft tissues and the bones. Lead poisoning has been documented from ancient Rome, ancient Greece, and ancient China.
Other articles related to "lead":
... mills were being used for preparing lead ... Sheets of lead were placed in clay pots and submerged in urine, then heated by decaying cow dung ... The process converted the lead to lead oxide, and it was then finely ground to form a pigment for white, yellow and red lead paint ...
... substitute for lemon yellow pigments such as the cadmium sulfides and the lead/strontium/barium chromates ... Unlike lead chromate+lead sulfate lemon, bismuth vanadate does not readily blacken with UV exposure ...
... In the human body, lead inhibits porphobilinogen synthase and ferrochelatase, preventing both porphobilinogen formation and the incorporation of iron into protoporphyrin IX, the final step in heme synthesis ... Acute lead poisoning is treated using disodium calcium edetate the calcium chelate of the disodium salt of ethylene-diamine-tetracetic acid (EDTA) ... This chelating agent has a greater affinity for lead than for calcium and so the lead chelate is formed by exchange ...
... The Beatles John Lennon – lead, harmony and backing vocals, rhythm and acoustic guitars, piano, harmonica, tambourine, handclaps 12-string lead guitar on "Every ...
... The Lead has to communicate the direction of the movement to the Follow ... Traditionally, the Lead's right hand on the follow's back, near the lowest part of the shoulder-blade ... This is the strongest part of the back and the lead can easily pull the Follow's body inwards ...
Famous quotes containing the word lead:
“Yet let him keep the rest,
But keep them with repining restlessness:
Let him be rich and weary, that at least,
If goodness lead him not, yet weariness
May toss him to My breast.”
—George Herbert (15931633)
“We fear our neighbors hostile mood because we are afraid that this mood will lead him to penetrate our secrets.”
—Friedrich Nietzsche (18441900)
“As a friend to the children commend me the Yak.
You will find it exactly the thing:
It will carry and fetch, you can ride on its back,
Or lead it about with a string.”
—Hilaire Belloc (18701953)