Search results
Results From The WOW.Com Content Network
Selenium is commonly described as a metalloid in the environmental chemistry literature. [450] It moves through the aquatic environment similarly to arsenic and antimony; [ 451 ] its water-soluble salts, in higher concentrations, have a similar toxicological profile to that of arsenic.
[n 5] One or more of carbon, aluminium, phosphorus, selenium, tin or bismuth, these being periodic table neighbours of the elements commonly classified as metalloids, are sometimes recognised as metalloids. [n 6] Selenium, in particular, is commonly designated as a metalloid in environmental chemistry [n 7] on account of similarities in its ...
Selenium is found in metal sulfide ores, where it substitutes for sulfur. Commercially, selenium is produced as a byproduct in the refining of these ores. Minerals that are pure selenide or selenate compounds are rare. The chief commercial uses for selenium today are glassmaking and pigments. Selenium is a semiconductor and is used in photocells.
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.
Selenium forms a series of anionic selenites and selenates such as Na 2 SeO 3, Na 2 Se 2 O 5, and Na 2 SeO 4, [158] as well as Zintl phases such as Cs 4 Se 16. [159] Tellurium is a soft (MH 2.25) and brittle semi-metallic element. It is commonly regarded as a metalloid, or by some authors either as a metal or a non-metal.
This results in six or seven sets of nonmetals, depending on the treatment of boron, which in some cases is regarded as a metalloid. The size of the group 14 set, and the sets of nonmetal pnictogens, chalcogens, and halogens will vary depending on how silicon, germanium, arsenic, antimony, selenium, tellurium, and astatine are treated.
The chemistry of selenium is largely covalent in nature, noting it can form ionic selenides with highly electropositive metals. The common oxide of selenium (SeO 3) is strongly acidic. Tellurium. Tellurium is a silvery-white, moderately reactive, [8] shiny solid, that has a density of 6.24 g/cm 3 and is soft (MH 2.25) and brittle. It is the ...
Organometallic chemistry is the study of organometallic compounds, chemical compounds containing at least one chemical bond between a carbon atom of an organic molecule and a metal, including alkali, alkaline earth, and transition metals, and sometimes broadened to include metalloids like boron, silicon, and selenium, as well.