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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 it has been argued that the term "heavy metal" should be avoided.
Many metals, particularly heavy metals are toxic, but some are essential, and some, such as bismuth, have a low toxicity. Metals in an oxidation state abnormal to the body may also become toxic: chromium(III) is an essential trace element, but chromium(VI) is a carcinogen. Only soluble metal-containing compounds are toxic.
A heavy metal is any relatively dense metal, either single element or multielement. [46] Magnesium, aluminium and titanium alloys are light metals of significant commercial importance. [47] Their densities of 1.7, 2.7 and 4.5 g/cm 3 range from 19 to 56% of the densities of other structural metals, [48] such as iron (7.9) and copper (8.9) and ...
Researchers agree that avoiding heavy metals entirely in our diet is nearly impossible. Foods such as rice, fish, fruits and vegetables have been known to contain varying amounts of metals.
The chemical elements can be broadly divided into metals, metalloids, and nonmetals according to their shared physical and chemical properties.All elemental metals have a shiny appearance (at least when freshly polished); are good conductors of heat and electricity; form alloys with other metallic elements; and have at least one basic oxide.
A toxic heavy metal is a common but misleading term for a metal-like element noted for its potential toxicity. [4] Not all heavy metals are toxic and some toxic metals are not heavy. [ 5 ] Elements often discussed as toxic include cadmium , mercury and lead , [ 6 ] all of which appear in the World Health Organization 's list of 10 chemicals of ...
Most of the normal currently detectable (i.e. non-dark) matter in the universe is either hydrogen or helium, and astronomers use the word "metals" as convenient shorthand for "all elements except hydrogen and helium". This word-use is distinct from the conventional chemical or physical definition of a metal as an electrically conducting solid.
The use of unleaded paints and gas has successfully decreased the number of cases of lead heavy metal poisoning. Nickel, chromium, and cadmium: via metal-DNA interactions, these metals can be carcinogenic. [3] Nickel: allergies to nickel, particularly from skin to metal contact via jewelry, are common.