Nitrogen is a chemical element with atomic number 7. It is an odorless, tasteless, and colorless gas.
Therefore, humans do not sense nitrogen in the earth’s atmosphere, whereas it comprises 78 percent of this substance. Nitrogen is one of the most common substances on our planet. One often hears that without nitrogen, there would be no life on Earth, and it is true. After all, the protein compounds that make up all life contain nitrogen.
Nitrogen in nature
Nitrogen is found in the atmosphere as molecules comprising two atoms. Besides the atmosphere, there is nitrogen in the Earth’s mantle and in the humus layer of soil. The major source of nitrogen for industrial production is minerals.
However, in recent decades, as mineral reserves have become depleted, there has been an urgent need to extract nitrogen from the air on an industrial scale. This problem has now been solved, and vast quantities of nitrogen for industrial needs are extracted from the atmosphere.
Role of nitrogen in biology, nitrogen cycle
On Earth, nitrogen undergoes a series of transformations involving both biotic (life-related) and abiotic factors. From the atmosphere and soil, nitrogen enters plants, not directly, but through microorganisms. Nitrogen-fixing bacteria keep and recycle nitrogen, turning it into a form easily assimilated by plants. In plants, nitrogen is converted into complex compounds, in particular – proteins.
Through the food chain, these substances enter the organisms of herbivores and then predators. After the death of all life, nitrogen enters the soil again, where it undergoes decomposition (ammonification and denitrification). The nitrogen is fixed in the soil, minerals, and water enters the atmosphere, and the circle repeats.
Applications of Nitrogen
Since the discovery of nitrogen (this happened in the 18th century), the properties of the substance itself, its compounds, and the possibilities of its use in agriculture have been well studied. Since the reserves of nitrogen on our planet are enormous, this element became extremely actively used.
Pure nitrogen is used in liquid or gaseous form. Liquid nitrogen has a temperature of minus 196 degrees Celsius and is used in the following areas:
– Medicine. Liquid nitrogen is a refrigerant in cryotherapy procedures, i.e. cold therapy. Instant freezing is used to remove various neoplasms. Tissue samples and living cells (sperm and eggs in particular) are stored in liquid nitrogen. The low temperature makes it possible to preserve the biomaterial for a long time and then defrost and use it.
The possibility of storing whole living organisms in liquid nitrogen and defrosting them with no harm has been expressed by science fiction writers. However, in reality, it has not yet been possible to master this technology;
– In the food industry, liquid nitrogen is used for bottling liquids to create an inert environment in the containers.
Nitrogen is used in applications where a gaseous environment without oxygen is required, e.g.
– in firefighting. Nitrogen displaces oxygen, without which combustion processes are not supported and the fire dies out.
Nitrogen gas is used in such industries:
– Food production. Nitrogen is used as an inert gas medium to keep products fresh in packaging;
– in oil production and mining. Nitrogen is used to purge pipelines and reservoirs. It is injected into mines to form an explosion-proof gas environment;
– in aircraft construction, nitrogen is used to inflate chassis tires.
All the above applies to the use of pure nitrogen, but it should not be forgotten that this element is a raw material for the production of all kinds of compounds:
– ammonia. An extremely demanded substance with nitrogen content. Ammonia is used for the production of fertilizers, polymers, soda, and nitric acid. It is used by itself in medicine, manufacture of refrigeration equipment;
– nitrogen fertilizers;
– dyes, etc.
Nitrogen is not only one of the most common chemical elements but also a very necessary component used in many branches of human activity.