Inert gases are general concepts, properties and applications

Inert gases, also called noble gases, occupy the main subgroup of the eighth group of the periodic system. There are only six of them: helium (He), neon (Ne), argon (Ar), xenon (Xe) and radon (Rn). To understand nature, let us first consider the notion of inertia. Inertia is a weak expression or lack of ability to react with other chemical elements. It is almost impossible to cause a chemical reaction to form new bonds in such substances.

Accordingly, an inert gas is a rare noble monatomic gas, which has a high inertia, which is due to the energy-stable external level of the electron shell of the atom. For example, helium in this shell has two electrons, and for other noble gases - eight. This explains their physical and chemical properties. All inert gases under normal conditions are colorless gases that are odorless and poorly soluble in water. Their boiling and melting points increase in accordance with the increase in the dimensions of the atoms.

Until 1962, scientists were sure that all noble gases are absolutely inert. But the Canadian chemist N. Bartlett was able to prove the opposite, having received the first chemical compound of xenon, the so-called hexafluoroplatinate of xenon. This compound is a solid orange substance with a crystal lattice. Later, a number of compounds were significantly expanded.

Prevalence and education in nature

In the universe of noble gases, helium is most common, and in terrestrial conditions - argon (in volume it occupies 0.934%). In very small quantities, inert gases are present in rocks and in gases of natural combustible materials, and in dissolved form they can be found in oil and water.

Under natural conditions, noble gases can form as a result of various nuclear reactions. For example, radioactive uranium is the source of radon. Some of these chemical elements are of cosmogenic origin.

All inert gases, except for the parent, have a number of isotopes.

The reserves of these gases do not decrease. Only helium is gradually, very slowly, scattered in interstellar space.

Application

Inert gases have found wide application in the field of electrical engineering. Argon, in view of its inactivity and low thermal conductivity, is used in a mixture with nitrogen to fill electric lamps. Argon and neon fill tubes for light advertising, while they glow blue, and neon - orange-red.

Argon is also used in chemical laboratory practice. In industry, it has found its application for the thermal treatment of easily oxidizable metals. Argon creates a protective atmosphere in which it is possible to weld or cut rare and non-ferrous metals, melting tungsten, titanium, zirconium. To control the ventilation systems, a radioactive isotope of argon is used.

Krypton and xenon have an even lower thermal conductivity than argon, so the electric bulbs filled with them are more durable and economical than those filled with nitrogen or argon.

The divers breathe a mixture of helium and oxygen, which allows them to significantly extend the time of their stay under water and dramatically weakens the painful phenomena caused by a change in pressure when rising to the surface.

Liquid helium is used as a coolant in various studies, since the boiling point of this gas is -268.9 ° C.

The property of complete inertia of helium is used for welding in its atmosphere, for the production of ultrapure metals, and chromatography. And its high permeability allowed to create leak detectors in low and high pressure apparatus.