A metalloid, also called a semimetal, is any of a class of chemical elements intermediate in properties between metals and nonmetals. The classification is not clear cut, but the generally recognized metalloids – boron (B), silicon (Si), germanium (Ge), arsenic (As), antimony (Sb), selenium (Se), and tellurium (Te) – form a diagonal band in the periodic table. They are electrical semiconductors and their oxides are amphoteric.