Silicon is a chemical element (its symbol in chemical formula expressions is "Si") that is present in sand and glass and which is the best known semiconductor material in electronic components. Its atomic number is 14. The most common isotope has atomic weight 28. In its pure state, silicon is a metal-like substance with an appearance and heft somewhat resembling aluminum. In its natural state, silicon appears bound up with other elements in the form of compounds. It is abundant in the crust of the earth.
Silicon conducts electricity to an extent that depends on the extent to which impurities are added. The addition of impurities to silicon, or to any semiconductor material, is called doping . Some impurities produce N-type silicon, in which the majority charge carriers are negatively charged electron s. Other impurities result in the production of P-type silicon, in which the majority charge carriers are positively charged hole s. Most silicon devices contain both N-type and P-type material.
Silicon is used in a wide variety of electronic and computer components, including: