Silicon is neither metal nor non-metal; it's a metalloid, an element that falls somewhere between the two. The category of metalloid is something of a gray area, with no firm definition of what fits the bill, but metalloids generally have properties of both metals and non-metals. They look metallic, but conduct electricity only intermediately well. Silicon is a semiconductor, meaning that it does conduct electricity. Unlike a typical metal, however, silicon gets better at conducting electricity as the temperature increases (metals get worse at conductivity at higher temperatures).