A brittle metalloid element with symbol Si and atomic number 14 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.
a tetravalent nonmetallic element; next to oxygen it is the most abundant element in the earth's crust; occurs in clay and feldspar and granite and quartz and sand; used as a semiconductor in transistors
a tetravalent nonmetallic element; next to oxygen it is the most abundant element in the earth''s crust; occurs in clay and feldspar and granite and quartz and sand; used as a semiconductor in transistors
