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Lead (/ l ɛ d /) is a chemical element; it has symbol Pb (from Latin plumbum) and atomic number 82. It is a heavy metal that is denser than most common materials. Lead is soft and malleable, and also has a relatively low melting point. When freshly cut, lead is a shiny gray with a hint of blue. It tarnishes to a dull gray color when exposed to ...
Heavy metals is a controversial and ambiguous term [2] for metallic elements with relatively high densities, atomic weights, or atomic numbers.The criteria used, and whether metalloids are included, vary depending on the author and context and has been argued should not be used.
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.
Although lead has been banned from paint since 1978, lead poisoning still occurs. A medical expert explains the signs and symptoms of this public health problem.
The World Health Organization (WHO) specifically notes that there is "no known safe blood lead concentration," and that even blood lead concentrations as low as 3.5 µg/dL (micrograms per ...
Leaded copper is a metal alloy of copper with lead. A small amount of lead makes the copper easier to machine. Alloys with a larger amount of lead are used for bearings. Brass and bronze alloys of copper may have lead added and are then also sometimes referred to as leaded copper alloys. [1] Leaded copper and its alloys have been used since ...
Lead Free Mama, LLC, tested the 32 ounce Hydroflask in 2017 and deemed it lead free, and more recently added the bottle to a 2023 round up of favorite lead-free water bottles. Owala. Owala took to ...
Osmium is a hard, brittle, blue-gray metal, and the densest stable element—about twice as dense as lead. The density of osmium is slightly greater than that of iridium ; the two are so similar (22.587 versus 22.562 g/cm 3 at 20 °C) that each was at one time considered to be the densest element.