Classes of Elements

The smallest class of elements has properties of both metals and nonmetals. These elements are called metalloids. Examples of metalloids include silicon, germanium, and boron. All metalloids are solids and can be shiny or dull in appearance. Some metalloids are malleable but some are brittle. These elements have 3-7 electrons in their outer shell and can form bonds in similar ways as metals and nonmetals. Metalloids conduct heat and electricity, but not as well as metals. Semiconductors, made of such metalloids as silicon, can conduct electricity under certain conditions. Semiconductors are used to make electronic components like computer chips. Metalloids are also useful when combined with metals to form alloys. Pewter is an alloy that contains the metalloid antimony.