It is classified as metalloid or semimetal to an element that is not metal and is also not a nonmetal, in relation to ionization or bonding properties. Metalloids show an intermediate behavior between both groups and that is why they are located forming a diagonal between nonmetals and metals in the periodic table.
The elements are considered metalloids: boron (B), silicon (Si), germanium (Ge), arsenic (As), tellurium (Te), polonium (Po) and antimony (Sb).
Metalloids share certain characteristics with metals and others with non-metals. However, they have certain common properties that define them.
Properties of metalloids
- Density. Metalloids have densities intermediate between those of nonmetals and those of metals.
- Malleability and melting point. They are usually not very malleable, brittle and their melting point is high. In addition, they are hard elements.
- Chemical reactions. Metalloids do not participate in a single type of chemical reaction, but can have different reactions. They are generally amphoteric, so they can react with acids and bases at the same time, although they are also slightly acidic.
- Coloration. Most metalloids are grayish in color, although some may have differences in coloration. Some metalloids have polychromism, that is, several colors. As for their shine, they often present metallic shine (although there are some that are opaque). For example: One of the silicon variants is almost brown in color, while another is blue with a metallic luster. On the other hand, one variant of boron is brown and the other is black with a metallic luster.
- Conductivity. They are better conductors of electricity and heat than non-metals, but not as good as metals. They are called semiconductors.
- State of aggregation. Most are solid at room temperature. Arsenic, for example, is found in the form of sulfides, very rarely in a solid state.
- Degree of toxicity. Although in minute quantities, some of the metalloids are essential for the formation of molecules in the body of various living organisms, they can be highly toxic and lethal if found in considerable quantities.
- Chemical bond. As metalloids have intermediate properties between metals and nonmetals, the chemical bonds that they can form depend on the role they play in each chemical compound that they form.
- Abundance. There are some metalloids, such as silicon, which are found abundantly in the earth’s crust. Others, such as antimony and polonium, are less abundant in the earth’s crust.
Uses of metalloids
In most cases, metalloids are used for transistor manufacturing, circuits, appliance chips, LED lamps and photovoltaic cells. They are also used as flame retardants and mixtures of preparations for the construction of pyrotechnics.