Air

gas

at sea level, at 20 °C is approx 1.2 kg/m³

N2, O2, Ar, CO2 and approximately 1% of remaining gases

colourless

A colourless, odourless, tasteless homogeneous mixture of gases such as nitrogen (78%), oxygen (21%), carbon dioxide, argon and other gases which contain trace amounts; the density of air depends on the pressure and temperature conditions in which it is found, as well as on its exact composition; the air contains a different amount of water vapor, depending on the ambient conditions; the water vapor content in the air depends on many factors and varies in the range of 0–4%

It is an essential substance for the proper functioning of all living organisms on Earth; compressed air (i.e. air under appropriate pressure) is used as an energy carrier; in pneumatics, compressed air is prepared in special devices; devices using pneumatic systems are used in many industries, such as the automotive industry, all types of workshop and specialized tools; is used for the operation of combustion engines as one of the components of the mixture combusted in the engine; the energy of moving air, i.e. wind, is used to produce green energy on so-called wind farms; air for use in metallurgy, e.g. in steel converting processes

Most of our oxygen comes not from the forest, but from the sea; oceanic algae produce most of the oxygen in the atmosphere; these plants may be tiny, but due to their sheer numbers, they are able to pump out tons of clean air for us to breathe; on average, a person takes approximately 20,000 breaths per day; air pollution is a serious problem today (approximately 98% of air pollution is caused by human activities); people on the international space station have noted that over some places on our planet the atmosphere is polluted to the point that it appears gray; the air in our atmosphere acts as insulation, keeping the Earth from getting too cold or too hot; ozone, another type of gas in the air, also protects us from excessive sunlight; the air in the atmosphere can also protect us from meteoroids, when meteoroids come into contact with our atmosphere, they rub against the air and often get burned into small pieces before they reach the Earth; even on a very calm day, the air around us is always moving, and when the wind picks up seeds, dust, and other particles, it can carry them many miles away from their original home