It is most widely distributed in dusts, sands, planetoids, and planets as various forms of silicon dioxide (silica) or silicates.
A hard and brittle crystalline solid with a blue-gray metallic luster, it is a tetravalent metalloid.
It is a member of group 14 in the periodic table, along with carbon above it and germanium, tin, lead, and flerovium below.
It is rather unreactive, though less so than germanium, and has great chemical affinity for oxygen; as such, it was first prepared and characterized in pure form only in 1823 by J? Silicon is the eighth most common element in the universe by mass, but very rarely occurs as the pure element in the Earth's crust.
The outer electron orbital of silicon, like that of carbon, has four valence electrons.
The 1s, 2s, 2p and 3s subshells are completely filled while the 3p subshell contains two electrons out of a possible six. It has a negative temperature coefficient of resistance, since the number of free charge carriers increases with temperature.