The elements on the periodic table that display some characteristics of metals and nonmetals are categorized as metalloids. Metalloids are elements that have properties of both metals and nonmetals. They are located in the p-block of the periodic table, and they include boron, silicon, germanium, arsenic, antimony, tellurium, and polonium. Metalloids have a metallic luster and are good conductors of electricity and heat, but they are not as malleable or ductile as metals. They also have some of the properties of nonmetals, such as the ability to form covalent bonds and to react with oxygen to form oxides.