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Lead-210 is particularly useful for helping to identify the ages of samples by measuring its ratio to lead-206 (both isotopes are present in a single decay chain). [51] In total, 43 lead isotopes have been synthesized, with mass numbers 178–220. [38] Lead-205 is the most stable radioisotope, with a half-life of around 1.70 × 10 7 years.
James Andrew Harris (March 26, 1932 – December 12, 2000) was an American radiochemist who was involved in the discovery of elements 104 and 105 (rutherfordium and dubnium, respectively). Harris was the head of the Heavy Isotopes Production Group, part of the Nuclear Chemistry Division of the University of California, Berkeley .
Lead (Pb) is a heavy trace element and is formed by the radioactive decay of uranium and thorium. In crustal rocks, it is present as the lead sulfide mineral galena . [ 1 ] Natural sources of lead in the lead cycle include wind borne dust, volcanic outgassing, and forest fires. [ 2 ]
Galena, also called lead glance, is the natural mineral form of lead(II) sulfide (PbS). It is the most important ore of lead and an important source of silver. [5] Galena is one of the most abundant and widely distributed sulfide minerals. It crystallizes in the cubic crystal system often showing octahedral forms.
Lead poisoning in children is usually caused by swallowing or breathing in dust form lead-based paint, but lead can also be found in the soil and air from car, plane and factory emissions, and ...
Before Thomson's model, atoms were simply the basic units of weight by which the chemical elements react. Thomson himself was a physicist and his atomic model was a byproduct of his investigations of cathode rays, by which he discovered the negatively charged particles now known as electrons. Thomson hypothesized that the quantity, arrangement ...
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Lead (sea ice), a temporary stretch of open water in pack ice; Lead compound, a chemical compound in drug discovery (not necessarily with lead the metal) Pencil lead, the graphite ("lead"), the writing core of a pencil; Sounding lead or sounding line, a line used to measure water depth; Tetraethyllead or lead, a gasoline additive