二氧化硅/二氧化矽 10分!!!

二氧化硅=二氧化矽
The chemical compound silicon dioxide, also known as silica, is the oxide of silicon, chemical formula SiO2. Siliceous is an adjective meaning "referring to silica"
In nature
Silica is found in nature in several forms, including quartz and opal. In fact, it has 17 crystalline forms (see Nomenclature of Silica).
The most common constituent of sand in inland continental settings and non-tropical coastal settings is silica, usually in the form of quartz because the considerable hardness of this mineral resists erosion. However, the composition of sand varies according to local rock sources and conditions.
Variants found in high-pressure impacts are coesite and stishovite.
Many forms of life contain silica structures (biogenic silica), including microorganisms such as diatoms, plants such as horsetail, and animals such as hexactinellid sponges. It is present in the cell walls of various plants (including edible ones) to strengthen their structural integrity. silica is used in plaster,this can have health implications for plasterers children when work clothes and kids clothes are washed together.microscopic particles of glass are held in the clothing and rubbed against the skin causeing abrasion scars that go undiaognosed at the doctors
Health effects
Inhaling crystalline silica dust can lead to silicosis or cancer.
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Homeopathic use
Silicon dioxide (silica) is widely used as a homeopathic remedy to treat impure blood, boils, brittle nails and lack-lustre hair. The homeopathic usage of Silicon Dioxide was introduced in the 19th century by http://www.biochemics.info/biochemistry.htm Dr. Wilhelm Heinrich Schüßler] (1821-1898) through his biochemic method of healing.
There is no experimental or clinical evidence that silica is of actual medical value.
Dr. Schüßler, a doctor of medicine, physiological chemist and a physicist concluded that the normal functioning of cells are dependant on a normal dosage of 12 inorganic mineral salts, one of which included Silicon Dioxide.
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Chemistry
Silicon dioxide is formed when silicon is exposed to oxygen (or air). A very thin layer (approximately 10 Angstroms) of so-called 'native oxide' is formed on the surface when silicon is exposed to air under ambient conditions. Higher temperatures and alternate environments are used to grow well-controlled layers of silicon dioxide on silicon.
Silicon dioxide is attacked by hydrofluoric acid (HF). HF is used to remove or pattern silicon dioxide in the semiconductor industry.
Beau is made of Silica.
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Reference

R. K. Iler, The Chemistry of Silica (ISBN 0-471-02404-X)
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See also

Amorphous carbonia
Fused silica
Quartz
Glass
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External links

International Chemical Safety Card 0807 (Tridymite)
International Chemical Safety Card 0808 (Quartz)
International Chemical Safety Card 0809 (Cristobalite)
NIOSH Pocket Guide to Chemical Hazards (amorphous)
NIOSH Pocket Guide to Chemical Hazards (crystalline, as respirable dust)

Link page to external chemical sources.
詳情 : http://en.wikipedia.org/wiki/Silicon_dioxide