The heaviest gas. Radioactive gas radon: properties, characteristics, half-life

Gas is one of the aggregate states of matter. Gases are present not only in the air on Earth, but also in space. They are associated with ease, weightlessness, volatility. The easiest is hydrogen. And which gas is the heaviest? Let's find out.

The heaviest gases

The word "gas" comes from the Greek word"chaos". Its particles are mobile and weakly connected with each other. They move chaotically, filling themselves with all the space available to them. The gas can be a simple element and consist of atoms of one substance, and can be a compound of several.

The simplest heavy gas (in room conditionstemperature) is radon, its molar mass is 222 g / mol. It is radioactive and absolutely colorless. After it, the heaviest is xenon, whose atomic mass is 131 g / mol. The remaining heavy gases are compounds.

Among the inorganic compounds, the heaviest gas at a temperature of +20 ^aboutC is tungsten fluoride (VI). Its molar mass is 297.84 g / mol, and the density is 12.9 g / l. Under normal conditions, it is a colorless gas, in damp air it smokes and turns blue. Tungsten hexafluoride is very active, it is easily converted to liquid upon cooling.

Radon

The discovery of gas occurred during thestudy of radioactivity. In the course of the disintegration of certain elements, scientists repeatedly noted a substance emitted along with other particles. E. Rutherford called it emanation.

Thus, the emanation of thorium - thoron, radium- radon, actinium - actinone. Later it was established that all these emanations are isotopes of the same element - an inert gas. Robert Gray and William Ramsay first isolated it in its pure form and measured its properties.

In the periodic table of Mendeleyev radon iselement of the 18th group with atomic number 86. It is located between the astatine and France. Under normal conditions, the substance is a gas, has no taste, odor and color.

The gas is 7.5 times denser than air. It dissolves in water better than other noble gases. In solvents, this figure is even greater. Of all inert gases, it is the most active, easily interacting with fluorine and oxygen.

Radioactive gas radon

One of the properties of the element is radioactivity. Element has about thirty isotopes: four natural, the rest - artificial. All of them are unstable and are subject to radioactive decay. The half-life of radon, more precisely, its most stable isotope, is 3.8 days.

Because of the high radioactivity, the gas possessesfluorescence. In the gaseous and liquid state, the substance is highlighted in blue. Solid radon changes its palette from yellow to red when cooled to a nitrogen temperature - about -160 ^aboutFROM.

Radon can be very toxic to humans. As a result of its breakdown, heavy non-volatile products are formed, for example, polonium, lead, bismuth. They are extremely poorly excreted from the body. By settling and accumulating, these substances poison the body. After smoking, radon is the second most common cause of lung cancer.

Location and application of radon

The heaviest gas is one of the rarestelements of the earth's crust. In nature radon is a part of ores with the content of uranium-238, thorium-232, uranium-235. When they decay, it is released, falling into the hydrosphere and the Earth's atmosphere.

Radon accumulates in river and sea waters, inplants and soil, in building materials. In the atmosphere, its content increases with the activity of volcanoes and earthquakes, during the extraction of phosphates and the work of geothermal power stations.

With the help of this gas, tectonicfaults, deposits of thorium and uranium. It is used in agriculture to activate pet food. Radon is used in metallurgy, when studying groundwater in hydrology, radon baths are popular in medicine.