Gas is one of the aggregative states of matter. Gases are present not only in the air on Earth, but also in space. They are associated with lightness, weightlessness, volatility. The lightest is hydrogen. What is the heaviest gas? Let's find out.
The heaviest gases
The word "gas" comes from the ancient Greek word "chaos". Its particles are mobile and weakly connected with each other. They move randomly, filling with themselves all the space available to them. A gas can be a simple element and consist of atoms of one substance, or it can be a combination of several.
The simplest heavy gas (at room temperature) is radon, its molar mass is 222 g / mol. It is radioactive and completely colorless. After it, the most severe is xenon, whose atomic mass is 131 g / mol. The remaining heavy gases are compounds.
Among inorganic compounds, the heaviest gas at a temperature of +20 ° C is tungsten (VI) fluoride. Its molar mass is 297.84 g / mol and its density is 12.9 g / l. Under normal conditions, it is a colorless gas; in humid 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 research on the study of radioactivity. During the decay of some elements, scientists have repeatedly noted some substance emitted along with other particles. E. Rutherford called it an emanation.
So the emanation of thorium - thoron, radium - radon, actinium - actinon was discovered. It was later 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, radon is an element of group 18 with atomic number 86. It is located between astatine and France. Under normal conditions, the substance is a gas, has no taste, smell, or color.
Gas is 7.5 times denser than air. It dissolves in water better than other noble gases. In solvents, this indicator is further increased. 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. The element has about thirty isotopes: four are natural, the rest are artificial. All of them are unstable and subject to radioactive decay. The half-life of radon, more precisely, its most stable isotope, is 3.8 days.
Due to its high radioactivity, the gas exhibits fluorescence. In a gaseous and liquid state, the substance is highlighted in blue. Solid radon changes its palette from yellow to red when cooled to a temperature of nitrogen - about -160 ° C.
Radon can be very toxic to humans. As a result of its decay, heavy non-volatile products are formed, for example, polonium, lead, bismuth. They are extremely poorly excreted from the body. Settling and accumulating, these substances poison the body. After smoking, radon is the second most common cause of lung cancer.
Location and use of radon
The heaviest gas is one of the rarest elements of the earth's crust. In nature, radon is part of ores containing uranium-238, thorium-232, and uranium-235. When they decay, it is released, falling into the hydrosphere and atmosphere of the Earth.
Radon accumulates in river and sea waters, in plants and soil, in building materials. In the atmosphere, its content increases with the activity of volcanoes and earthquakes, with the production of phosphates and the operation of geothermal power stations.
Using this gas, tectonic faults, deposits of thorium and uranium are found. It is used in agriculture to activate pet food. Radon is used in metallurgy, in the study of groundwater in hydrology, radon baths are popular in medicine.