The earliest military, industrial, and agricultural applications of nitrogen compounds used saltpetre sodium nitrate or potassium nitrate , most notably in gunpowder and later as fertilizer. Nitrogen is a chemical element with symbol N and atomic number 7. Elemental nitrogen is a colorless, odorless, tasteless, and mostly inert diatomic gas at standard conditions, constituting Nitrogen is a common element in the universe, estimated at about seventh in total abundance in our galaxy and the solar system.
Its occurrence there is thought to be entirely due to synthesis by fusion of carbon and hydrogen in supernovas. Due to the volatility of elemental nitrogen and its compounds with hydrogen and oxygen, nitrogen is far less common on the rocky planets of the inner solar system and is a relatively rare element on Earth.
However, as on Earth, nitrogen and its compounds occur commonly as gases in the atmospheres of planets and moons.
Nitrogen occurs in all living organisms, primarily in amino acids which make up proteins, and nucleic acids DNA and RNA. The human body is about three percent nitrogen by weight, the fourth-most abundant element after oxygen, carbon, and hydrogen.
Nitrogen resides in the chemical structure of almost all neurotransmitters and is a defining component of alkaloids, biological molecules produced as secondary metabolites by many organisms. The nitrogen cycle describes the movement of the element from the air into the biosphere and organic compounds and back into the atmosphere. It is also used in deep-sea diving, since helium is less soluble in the bloodstream than nitrogen, and reduces the risk of the diver suffering nitrogen narcosis, high pressure nervous syndrome HPNS , or the bends.
Breathing helium gas causes the voice to become higher pitched because helium is less dense than air, changing the frequency of the sound waves generated in the larynx. Neon is a colorless, odorless, unreactive gas which liquefies at Neon was discovered in by Sir William Ramsay see entry on Argon below and his assistant Morris Travers while working with a sample of krypton. The name comes from the Greek word for "new," neos. It is found in the Earth's crust at a concentration of 70 ppt, making it the 80th most abundant element; it is found in the atmosphere at a concentration of 18 ppm by volume.
Neon which is used commercially is extracted from liquid air by fractional distillation. Neon is used primarily in neon lights ; stimulating neon with electricity causes it to emit an intense red light. Other noble gases are used in "neon lights" as well, to produce different colors. Neon is also used in some underwater breathing mixtures; liquid neon is used in low-temperature cooling. Argon is a colorless, odorless, unreactive gas which liquefies at It is found in the Earth's crust at a concentration of 1.
Argon which is used commercially is extracted from liquid air by fractional distillation. Argon had been observed before by Henry Cavendish in , but it had not been identified as an element. Because of its unreactivity, it was named for the Greek word for "idle," argos. When argon was discovered, it didn't fit with the reactivities of any other element on the periodic table, and chemists realized that there might be a whole family of previously-unrecognized elements, which we now recognize as Group 8A.
Argon is used in light bulbs because it is inert to the hot metal of the bulb filament; the filament would burn out much faster in air or even pure nitrogen.
While chemical inertness and biological inertness are often the same, sometimes a substance can be one and not the other. For example, while xenon does not chemically react in the human body, it nonetheless has biological effects that have been exploited for anesthesia as well as improvement of tissue damage caused by inadequate blood supply ischemia. Inert materials are good choices for chemical containers. For example, acid waste should not be stored in metal drums because these will quickly corrode.
However, glass or polyethylene containers are inert to most acids. If a chemical spill occurs, one may need to clean up the spill by using an inert absorbing material such as vermiculite or sand. The Safety Data Sheet will usually recommend a specific material, but not always.
Assuming your SDS was created using the format required under HCS , spill cleanup information will be found under Section 6 accidental release measures. But be sure to read the rest of the sheet as well, because it's important that you know the physical properties of the material, the health hazards, incompatibilities etc. Safety Emporium has a great lineup of gas cylinder signs, storage racks, clamps and more. Bulk modulus A measure of how difficult it is to compress a substance. Vapour pressure A measure of the propensity of a substance to evaporate.
Pressure and temperature data — advanced. Listen to Nitrogen Podcast Transcript :. You're listening to Chemistry in its element brought to you by Chemistry World , the magazine of the Royal Society of Chemistry.
This week, we're blowing up airbags, asphyxiating animals and getting to the bottom of gunpowder because Cambridge chemist Peter Wothers has been probing the history of nitrogen. It's by far the most abundant element in its group in the periodic table and yet it is the last member of its family to be discovered. The other elements in its group, phosphorus, arsenic, antimony and bismuth, had all been discovered, used and abused at least years before nitrogen was known about.
It wasn't really until the 18 th Century that people focussed their attention on the chemistry of the air and the preparation properties of different gases. We can only really make sense of the discovery of nitrogen by also noting the discovery of some of these other gases. Robert Boyle noted in that when acid was added to iron filings, the mixture grew very hot and belched up copious and stinking fumes. So inflammable it was that upon the approach of a lighted candle to it, it would readily enough take fire and burn with a bluish and somewhat greenish flame.
Hydrogen was more carefully prepared and collected by the brilliant but reclusive millionaire scientist Henry Cavendish about a years later. Cavendish called the gas inflammable air from the metals in recognition of this most striking property. He also studied the gas we know call carbon dioxide, which had first been prepared by the Scottish chemist, Joseph Black in the s.
Black called carbon dioxide fixed air, since it was thought to be locked up or fixed in certain minerals such as limestone. It could be released from its stony prison by the action of heat or acids.
Carbon dioxide was also known by the name mephitic air the word mephitic meaning noxious or poisonous. This name obviously came from its property of destroying life, since it rapidly suffocates any animals immersed in it.
This is where the confusion with nitrogen gas begins, since pure nitrogen gas is also suffocating to animals. If the oxygen in an enclosed quantity of air is used up, either by burning a candle in it or by confining an animal, most of the oxygen is converted to carbon dioxide gas which mixes with the nitrogen gas present in the air.
This noxious mixture no longer supports life and so was called mephitic. The crucial experiment in the discovery of nitrogen was when it was realized that there are at least two different kinds of suffocating gases in this mephitic air.
This was done by passing the mixture of gases through a solution of alkali, which absorbed the carbon dioxide but left behind the nitrogen gas. Cavendish prepared nitrogen gas by this means. He passed air back and forth over heated charcoal which converted the oxygen in the air to carbon dioxide. The carbon dioxide was then dissolved in alkali leaving behind the inert nitrogen gas, which he correctly observed was slightly less dense than common air. Unfortunately, Cavendish didn't publish his findings.
He just communicated them in a letter to fellow scientist, Joseph Priestley, one of the discoverers of oxygen gas. Consequently, the discovery of nitrogen is usually accredited to one of Joseph Black's students, the Scottish scientist, Daniel Rutherford, who's also the uncle of the novelist and poet, Sir Walter Scott.
Rutherford published his findings, which was similar to those of Cavendish in his doctoral thesis entitled, "An Inaugural Dissertation on the Air called Fixed or Mephitic" in So what about the name, nitrogen? In the late s, chemical nomenclature underwent a major revolution under the guidance of the French chemist, Antoine Lavoisier. It was he and his colleagues, who suggested many of the names we still use today including the word hydrogen, which comes from the Greek meaning water former and oxygen from the Greek for acid producer, since Lavoisier mistakenly thought that oxygen was the key component of all acids.
However, in his list of the then known elements, Lavoisier included the term azote or azotic gas for what we now call nitrogen. This again stems from Greek words, this time meaning the absence of life, once again focussing on its mephitic quality.
It was not long before it was pointed out that there are many mephitic gases, in fact no gas other than oxygen can support life. The name nitrogen was therefore proposed from the observation, again first made by Cavendish that if the gases sparked with oxygen, and then the resulting nitrogen dioxide gases passed through alkali, nitre, otherwise known as saltpetre or potassium nitrate is formed.
The word nitrogen therefore means nitre former. The derivatives of the word, azote still survive today. The compound used to explosively fill car air bags with gas is sodium azide, a compound of just sodium and nitrogen.
When triggered this compound explosively decomposes freeing the nitrogen gas, which inflates the bags. Far from destroying life, this azotic compound has been responsible for saving thousands. Cambridge University's Peter Wothers telling the story of the discovery of nitrogen. Next time on Chemistry in its element, how chemists like Mendeleev got to grips with both the known and the unknown.
While other scientists had tried to create ways of ordering the known elements, Mendeleev created the system that could predict the existence of elements, not yet discovered. When he presented the table to the world in , it contained four prominent gaps.
One of these was just below manganese and Mendeleev predicted that element with atomic weight 43 would be found to fill that gap, but it was not until that a group of Italian scientists finally found the missing element, which they named technetium.
And you can hear Mark Peplow telling technetium's tale in next week's edition of Chemistry in its element. I'm Chris Smith, thank you for listening. See you next time. Chemistry in its element is brought to you by the Royal Society of Chemistry and produced by thenakedscientists. There's more information and other episodes of Chemistry in its element on our website at chemistryworld. Click here to view videos about Nitrogen.
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