Yes, SILICON is a Scrabble word!

Letter values in Scrabble US: S 1, I 1, L 1, I 1, C 3, O 1, N 1.

Is it a valid word?

SILICON is a valid word in the official Scrabble dictionary (US), the UK Scrabble Dictionary and Words with Friends (ENABLE).

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

Also: atomic number 14.