silicon

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

四価の非金属元素；酸素に次いで地殻中に最も多く存在する元素；粘土、長石、花崗岩、石英、砂に含まれる；トランジスタの半導体として用いられる