Selenium is most commonly produced from selenide in many sulfide ores, such as those of copper, nickel, or lead. Electrolytic metal refining is particularly conducive to producing selenium as a byproduct, and it is obtained from the anode mud of copper refineries.
https://en.wikipedia.org/wiki/Selenium
Dietary selenium comes from nuts, cereals, meat, mushrooms, fish, and eggs. Brazil nuts are the richest ordinary dietary source (though this is soil-dependent, since the Brazil nut does not require high levels of the element for its own needs).
https://en.wikipedia.org/wiki/Selenium
Overview. Selenium is a member of the chalcogen family. The chalcogens are elements in Group 16 (VIA) of the periodic table. The periodic table is a chart that shows how chemical elements are related to one another. Other chalcogens are oxygen, sulfur, tellurium, and polonium. The name chalcogen comes from the Greek word chatkos, meaning ore.. The first two members of the family, oxygen and sulfur, are found in most ores.
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Selenium is found in metal sulfide ores, where it partially replaces the sulfur. Commercially, selenium is produced as a byproduct in the refining of these ores, most often during production. Minerals that are pure selenide or selenate compounds are known, but are rare.
https://en.wikipedia.org/wiki/Selenium
Selenium is used in the toning of photographic prints, and it is sold as a toner by numerous photographic manufacturers. Its use intensifies and extends the tonal range of black-and-white photographic images and improves the permanence of prints. 75 Se is used as a gamma source in industrial radiography.
https://en.wikipedia.org/wiki/Selenium
Some of the most important physical characteristics of selenium are its electrical properties. For example, selenium is a semiconductor. A semiconductor is a substance that conducts an electric current better than non-conductors, but not as well as conductors.
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Selenium is a chemical element with symbol Se and atomic number 34. It is a nonmetal with properties that are intermediate between those of its periodic table column-adjacent chalcogen elements sulfur and tellurium. It rarely occurs in its elemental state in nature, or as pure ore compounds.
https://en.wikipedia.org/wiki/Selenium
Allotropes are forms of an element with different physical and chemical properties. One allotrope of selenium is an amorphous red powder. Amorphous means without crystalline shape.. A lump of clay is an example of an amorphous material.
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Health Hazard-Description of the chemical's health hazards (such as toxicity, flammability, or corrosivity). Reactivity Profile-Description of the chemical's potential reactivity with other chemicals, air, and water. Also includes any other intrinsic reactive hazards (such as polymerizable or peroxidizable). Reactive Groups-List of reactive groups that the chemical is assigned to, based on its known chemistry.
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The amorphous forms of selenium do not have specific melting points. Instead, they gradually become softer as they are heated. They may also change from one color and texture to another. The crystalline (metallic) form of selenium has a melting point of217°C (423°F) and a boiling point of 685°C (1,260°F).
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what is a chemical property of selenium
A chemical property of selenium is a nonmetal.