All elements of the periodic table are combined into groups, depending on their chemical properties. In this article we will analyze what halogens (or halogens) are.
The meaning of the concept of halogens
Halogens are elements from the periodic table of the 17th group, and according to the outdated classification, they are 7 main subgroups. Only 5 chemical elements belong to halogens, including fluorine, chlorine, iodine, astatine and bromine. All of them are non-metals. Halogens are very active oxidizing agents, and at the external level, these elements each have 7 electrons.
What are halogens, why did they get such a name? The word "halogen" was formed from two Greek words, which together mean "the birth of salt." One of the elements of this group is chlorine, together with sodium it forms a salt.
Physical properties of the halogen group
The chemical properties of halogens are similar, but the physical characteristics of the elements differ from each other.
Fluoride is a yellow gaseous substance with a very unpleasant and pungent odor. Chlorine is a green-yellow gas with a heavy and repulsive aroma. Bromine is a brown liquid. Astatine is a bluish-black solid with a pungent odor. Iodine is a gray solid. Summarizing the above information, we can answer the question: “What are halogens?”. These are gases, liquids, and solids.
Chemical properties of the halogen group
The main common property of all halogens is that they are all very active oxidizing agents. The most active halogen is fluorine, which reacts with all metals, and the most inactive is astatine.
Interaction with halogens in simple substances (with the exception of some non-metals) is easy. In nature, they are found only in the form of compounds.
Fluorine
Such a chemical element as fluorine was obtained only at the end of the 19th century by a French scientist named Henri Moissan. Fluoride is a pale yellow gas. Halogens are typical non-metals and oxidizing agents, and fluorine of all halogens is the most active. Now this halogen is indispensable in the industry because it is used in the manufacture of pipes, electrical tape, various fabric coatings, non-stick surfaces for pans and molds, and in medicine for the manufacture of artificial arteries and veins. In industry, this halogen is diluted with nitrogen.
Chlorine
Chlorine - a famous chemical element, belongs to the group of halogens. What are halogens, we have discussed above. Chlorine retains the basic properties of the elements of its group.
It received its name from the Greek word “chloros,” which translates as pale green. This gas is very widespread in nature, it is found in large quantities in seawater. Chlorine is a very important chemical element, it is almost indispensable for bleaching, disinfection of pools, as well as disinfection of drinking water.
But chlorine is also known for being the most dangerous deadly weapon. In 1915, German troops used about 6 thousand balloons with this halogen against the French army. This deadly weapon was invented by the famous German chemist Fritz Haber.
Iodine
Iodine, or iodine, is another chemical element that belongs to the halogen group. In fact, in the periodic table this element is called nothing more than iodine, but iodine is considered to be its trivial name. The name of the element comes from the Greek word, which in translation into Russian means "violet". This chemical element in everyday life is quite common. When interacting with other halogens, mainly with chlorine, an excellent means for disinfecting wounds and scratches is obtained. Now iodine is used in medicine for the prevention of thyroid diseases.
Astatine
Astatine is interesting in that it was never obtained by chemists in such a quantity that it could be seen with the naked eye. And most likely, this opportunity will never be presented to them. If experts could get a large amount of this chemical element, it would immediately evaporate due to the high temperature that occurs as a result of the radioactive radiation of this element. Astatine is the rarest chemical element, and a small amount of it is contained in the earth's crust.
Among halogens, astatine is a rather useless element, because at the moment no application has been found for it.
Application and meaning
Despite the fact that all halogens have similar chemical properties, they are used in completely different fields. For example, fluoride is very useful for teeth, which is why it is added to toothpastes. The use of therapeutic and prophylactic agents, in the composition of which the chemical element fluorine is present, prevents caries. Chlorine is used to produce hydrochloric acid, which is indispensable in industry and medicine. Chlorine is used to make rubber, plastics, solvents, dyes, and synthetic fibers. Compounds that contain this element are used in agriculture to control pests. Halogen chlorine is indispensable for bleaching paper and fabrics. It is believed that the use of chlorine for the treatment of drinking water is unsafe. Bromine, which is a halogen, as well as iodine is often used in medicine.
The value of halogens in human life is enormous. If we imagine the existence of mankind without halogens, then we would be deprived of such things as photographs, antiseptic and disinfectants, rubber, plastic, linoleum and many others. In addition, these substances are necessary for the human body to function normally, that is, they play an important biological role. Although the properties of halogens are similar, their role in industry and medicine is different.