We explain what metalloids are, what their uses and characteristics are. Also, the use of the term "semimetals".
What are metalloids?
Metalloids or semi-metals are a certain type of chemical elements that exhibit intermediate behavior between metallic and non-metallic elements, in regard to ionization issues and bonding properties. They are elements that act as metals in some situations and how no metals in others.
However, it is not easy to distinguish metalloids from true metals, and doing so generally requires a review of their metal properties. electrical conduction, as they are also usually very varied among themselves in shape, appearance and coloration.
The elements known as metalloids are the following:
- Boron (B).
- Silicon (Si).
- Germanium (Ge).
- Arsenic (Ar).
- Antimony (Sb).
- Tellurium (Te).
- Polonium (Po).
These elements are found, in the Periodic table, distributed on a descending diagonal from boron to astatine (not including the latter), between columns 13, 14, 15, 16 and 17, thereby dividing the entire table in two. The elements located in the right half are non-metallic and those located in the left half are metallic.
Metalloids are more or less rare in the Earth crust. Some are very abundant, such as silicon, which usually appears forming compounds called silicates, or also arsenic, or boron, found as part of the mineral borax, since it does not exist in a free and pure state in the nature.
Others, on the other hand, are quite rare, such as polonium, which appears as part of certain uranium minerals. Antimony, for example, is found in small percentages in the planet Earth.
Characteristics of metalloids
The metalloids are very varied in terms of their appearance, that is, shape and color. Some are shiny and others opaque, and many also have more than one allotropic state, that is, more than one presentation, depending on their molecular structure.
For example, arsenic can be gray, yellow, or black, depending on its allotropic version. Silicon, likewise, can appear as a shiny solid crystal, or as a shapeless, brownish powder.
Anyway, most metalloids are electrical semiconductors, that is, they conduct the electricity, but less than metals, which are conductors. Even so, they are much better conductors than nonmetals (which are usually insulators), which is why they have many industrial uses.
As with electricity, metalloids conduct the heat much better than non-metallic elements, but without reaching the high conductivity of metals.
Such an intermediate condition allows metalloids to react differently, depending on whether they are in the presence of a metal (in that case they will react as a nonmetal) or a nonmetal (then they will react as a metal). Generally speaking, they are quite reactive elements, rarely found in pure form in the nature and have three or more electrons in his cape Valencia.
For that same reason, they are usually toxic. Even some, such as arsenic, which are essential for the formation of molecules vital and are found in the body of living beings. In fact, boron or arsenic poisoning is often fatal; while polonium, for example, is not only toxic, but highly radioactive.
Uses of metalloids
Much of the chips and circuits are made of silicon.Mostly semimetals are useful in making electronic gadgets and other objects that use semiconductors, such as rectifiers, transistors, diodes, integrated circuits or even, in the case of silicon, for chips and microprocessors present in practically all the artifacts we use today.
However, being so varied, metalloids have other different uses, as part of pesticides, sealant materials or catalysts, such as some isotopes of Boron, for example, useful in the absorption of neutrons within nuclear power plants, thus functioning as regulating agents of atomic reactions.
Semimetals or metalloids?
Both terms are correct when naming this type of chemical elements: metalloids (that is, similar to metal) or semimetals (that is, they are not quite a metal). They can be used interchangeably.