|a. a brittle metalloid element that exists in two allotropic forms; occurs principally in sand, quartz, granite, feldspar, and clay. It is usually a grey crystalline solid but is also found as a brown amorphous powder. It is used in transistors, rectifiers, solar cells, and alloys. Its compounds are widely used in glass manufacture, the building industry, and in the form of silicones. Symbol: Si; atomic no: 14; atomic wt: 28.0855; valency: 4; relative density: 2.33; melting pt: 1414°C; boiling pt: 3267°C|
|b. (modifier; sometimes capital) denoting an area of a country that contains a density of high-technology industry|
|[C19: from |
silicon sil·i·con (sĭl'ĭ-kən, -kŏn')
A nonmetallic element occurring extensively in the earth's crust in silica and silicates, having both an amorphous and a crystalline allotrope and used in glass and semiconducting devices. Atomic number 14; atomic weight 28.086; melting point 1,414°C; boiling point 3,265°C; specific gravity 2.33; valence 4.
|silicon (sĭl'ĭ-kŏn') Pronunciation Key
A metalloid element that occurs in both gray crystalline and brown noncrystalline forms. It is the second most abundant element in the Earth's crust and can be found only in silica and silicates. Silicon is used in glass, semiconductors, concrete, and ceramics. Atomic number 14; atomic weight 28.086; melting point 1,410°C; boiling point 2,355°C; specific gravity 2.33; valence 4. See Periodic Table.