• Written By Kushal Jarwal
  • Last Modified 25-01-2023

Nitrogen: Definition, Structure, Density, Uses, Properties

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Nitrogen is everywhere! It is the most abundant gas present in the atmosphere, forming about 78% of Earth’s atmosphere. It is a significant contributor to life on this planet. It occurs in amino acids, DNA and RNA of all organisms. In the human body, Nitrogen is the the fourth most abundant element accounting for 3% of its total mass. Moreover, it is estimated as the seventh most commmon element in the Milky Way and the Solar System. Nitrogen is a nonmetallic chemical element represented by the symbol N. It is almost an inert gas and does not react quickly. Scottish physician Daniel Rutherford first isolated Nitrogen in 1772. The name nitrogène was coined by French chemist Jean-Antoine-Claude Chaptal in 1790. Read on to discover more amazing facts about nitrogen.

What is Nitrogen?

Definition: Nitrogen is a chemical element with an atomic symbol \({\rm{N}}\) atomic number of \(7\), and an atomic mass of \({\rm{14}}.{\rm{007}}\,{\rm{u}}.\) Nitrogen is present on Earth in abundance, as \(78\) per cent of the atmospheric gas is just Nitrogen; the rest is oxygen gas, around \(21\) per cent with traces of some other gases. In the atmosphere, Nitrogen exists as a diatomic molecule \({{\rm{N}}_2},\) which contributes to the growth of plants and animals like us. The \({{\rm{N}}_2}\) molecule has a unique triple bond within both the Nitrogen atoms, the second strongest diatomic bond between any two atoms. Hence, the reason for the inert behaviour of Nitrogen gas. Also, the electronic configuration of Nitrogen is \({\rm{1}}{{\rm{s}}^{\rm{2}}}{\rm{2}}{{\rm{s}}^{\rm{2}}}{\rm{2}}{{\rm{p}}^{\rm{3}}}{\rm{,}}\) which contributes to five valence electrons and is one of the most electronegative elements.

Nitrogen
Nitrogen symbol

The Density of Nitrogen

Density of nitrogen at STP (Standard Temperature and Pressure) is \({\rm{1}}.{\rm{2506}}\,{\rm{g/L}}.\)

Structure of Nitrogen Atom

Structure of Nitrogen

Properties of Nitrogen

  1. Nitrogen gas is a colourless, tasteless, and odourless gas.
  2. It is lighter than air.
  3. Nitrogen is a nonmetal having an electronegativity of \(3.04\).
  4. It has \(5\) electrons in its valence shell and is, hence, trivalent in most compounds
  5. The triple bond in \({{\rm{N}}_{\rm{2}}}\) is very strong.
  6. Electronic configuration of Nitrogen can be expressed as \(\left[ {{\rm{He}}} \right]{\rm{2}}{{\rm{s}}^{\rm{2}}}{\rm{2}}{{\rm{p}}^{\rm{3}}}\) or \({\rm{1}}{{\rm{s}}^{\rm{2}}}{\rm{\;2}}{{\rm{s}}^{\rm{2}}}{\rm{\;2}}{{\rm{p}}^{\rm{3}}}\) or \({\rm{1}}{{\rm{s}}^{\rm{2}}}{\rm{\;2}}{{\rm{s}}^{\rm{2}}}{\rm{\;2p}}{{\rm{x}}^{\rm{1}}}{\rm{2p}}{{\rm{y}}^{\rm{1}}}{\rm{2p}}{{\rm{z}}^{\rm{1}}}\) or \(\left( {2,5} \right).\)
  7. The Melting point of Nitrogen is \(- 210^\circ \,{\rm{C}}\)
  8. The Boiling point of Nitrogen is \(- 195.79^\circ \,{\rm{C}}\)
  9. The Relative atomic mass is \(14.007\).
  10. Nitrogen is slightly soluble in water.

Uses of Nitrogen

Nitrogen is used in a variety of things in day-to-day life.

1. Nitrogen helps plants to increase their rate of growth. So, it is used to produce fertilisers to increase the production of crops to meet the ever-rising demand for food by the growing population of humans.

Nitrogen used in production of crop

2. Nitrogen is the main component of explosives like TNT (Trinitrotoluene) and gunpowder, which has potassium nitrate in it as an essential component. Also, nitroglycerine is one of the dangerous explosives prepared by Nitrogen.

Nitrogen used in the production of nitroglycerine, a dangerous explosive

3. Nitrogen is used as a preserving material of food from rancidity. It is also used in incandescent lamps and bulbs instead of expensive argon gas.

4. Nitrogen can be used as fire extinguishing gas, sometimes filled in tyres to keep them cool.

5. Nitrogen is added in oxygen tanks while scuba diving to avoid narcosis which can be life endangering.

6. Nitrogen is used in preparing nitric acid, calcium cyanamide, ammonia and such industry-oriented chemicals.

7. Nitrogen gas provides an inert atmosphere in iron and steel industries and acts as a diluent in reactive chemicals to clutch down their reactiveness.

Nitrogen in Medical Science

Nitrogen in Medical Science

Nitrogen is one of the essential components of many medicines that we take today in our lives. It is used in cryosurgery removal of some cancers and is used to store the tissue samples for the future. Our body muscles are made up of proteins, and these proteins are composed of amino acids, which constitute Nitrogen. In other words, our body also is made up of nitrogen; after oxygen, carbon and hydrogen, nitrogen is the fourth most abundant element in the human body. Even our RNA and DNA have nitrogen in them, and the energy packets in our body consist of nitrogen as the main component.

Protein structure
Human body elements

How is Nitrogen Prepared?

From this article, we have understood that Nitrogen is an essential element for the livelihood of humans. Thus, we started extracting Nitrogen from the atmosphere and created various ways to prepare nitrogen for ourselves. There are two ways to prepare Nitrogen gas for ourselves, firstly by commercial means and laboratory methods.

Commercial Preparation of Nitrogen Gas: Nitrogen gas is prepared commercially by liquefying air and then separating the components of air with the help of fractional distillation. This is one of the easiest ways to procure nitrogen from the atmosphere and is quite a cheap process.

Fractional Distillation of Liquid Air

Laboratory Preparation of Nitrogen Gas: Nitrogen gas is prepared by thermal decomposition of ammonium nitrite. Though ammonium nitrate being unstable in heat is freshly prepared by ammonium chloride and sodium nitrite solution.

\({\rm{N}}{{\rm{H}}_4}{\rm{Cl}}({\rm{aq}}) + {\rm{NaN}}{{\rm{O}}_2}({\rm{aq}}) \to {\rm{N}}{{\rm{H}}_4}{\rm{N}}{{\rm{O}}_2}({\rm{aq}}) + {\rm{NaCl}}\left( {{\rm{aq}}} \right)\)

 

\({\rm{N}}{{\rm{H}}_4}{\rm{N}}{{\rm{O}}_2}({\rm{aq}}) \to {{\rm{N}}_2}({\rm{g}}) + 2{{\rm{H}}_2}{\rm{O}}\left( {\rm{l}} \right)\)

Nitrogen gas can be prepared by thermal decomposition of ammonium dichromate. Ammonium dichromate can be freshly prepared by reacting ammonium chloride with potassium dichromate.

\(\begin{array}{*{20}{l}} {{{\rm{K}}_2}{\rm{C}}{{\rm{r}}_2}{{\rm{O}}_7} + 2{\rm{N}}{{\rm{H}}_4}{\rm{Cl}} \to {{\left( {{\rm{N}}{{\rm{H}}_4}} \right)}_2}{\rm{C}}{{\rm{r}}_2}{{\rm{O}}_7} + 2{\rm{KCl}}}\\ {{{\left( {{\rm{N}}{{\rm{H}}_4}} \right)}_2}{\rm{C}}{{\rm{r}}_2}{{\rm{O}}_7} \to {{\rm{N}}_2}(\;{\rm{g}}) + 4{{\rm{H}}_2}{\rm{O}}({\rm{g}}) + {\rm{C}}{{\rm{r}}_2}{{\rm{O}}_3}(\;{\rm{s}})} \end{array}\)

Nitrogen gas can be prepared by thermal decomposition of Sodium azide. This reaction is used in airbags for car safety.

\(2{\rm{Na}}{{\rm{N}}_3}({\rm{g}}) \to 2{\rm{Na}}(s) + 3{{\rm{N}}_2}({\rm{g}})\)

Nitrogen Cycle

What is Nitrogen Cycle?

The nitrogen cycle is a biogeochemical process through which Nitrogen passes and gets converted to a variety of forms, Nitrogen moves from soil to plant to animal and then back to soil and atmosphere in different consecutive processes.

The different consecutive processes running simultaneously are:

  1. Nitrogen fixation
  2. Nitrification
  3. Denitrification
  4. Assimilation
  5. Ammonification
Cycle of Nitrogen

What is Nitrogen Fixation?

Nitrogen fixation is a beautiful process of converting atmospheric Nitrogen into usable Nitrogen compounds like ammonia, nitrates and nitrites with the help of some natural processes or in industries. A natural process for nitrogen fixation is done by some special kinds of bacteria like blue-green algae (or cyanobacteria), Anabaena, and Nostoc; and genera such as Azotobacter, Beijerinckia, and Clostridium; and mutualistic bacteria such as Rhizobium which takes atmospheric Nitrogen and converts it into nitrogen oxides which are further absorbed into the soil.

Also, nitrogen fixation can be done by some industrial processes. The atmospheric Nitrogen is tough to utilise because of the strong triple bond but after nitrogen fixation, plants can easily consume nitrogenous compounds present in soil and use them for growth.

What is Nitrification?

It is a process in which ammonium compounds with the help of bacteria, are converted into nitrates and nitrites.

What is Denitrification?

It is the process in which nitrates and nitrites are converted into nitrogen oxides or atmospheric Nitrogen with the help of bacteria.

What is Assimilation?

It is the process by which plants absorb the nitrogenous compounds produced during nitrification by bacteria by their roots into biomolecules like nucleic acids and proteins for their growth.

What is Ammonification?

The process by which bacteria break down the nitrogenous compounds into simpler substances like ammonia and its ionic products.

FAQs on Nitrogen

The most commonly asked questions on Nitrogen are answered here:

1. Do humans use Nitrogen?
Ans: Nitrogen is an element that is not used directly by humans from soil or air but is utilised indirectly with the help of plants in the form of vegetables and fruits as it helps in the growth of the human body as well. Also, Nitrogen is used in many medicines and has a variety of uses in human life.
2. Where is Nitrogen in the human body?
Ans: The human body consists of \(3\% \) of Nitrogen, and it is present in nucleic acids forming proteins which leads to the formation of muscles, and it is also present in our DNA and RNA.
3. What is the physical state of Nitrogen at STP?
Ans: It exists as a gas at standard temperature and pressure (STP) i.e., at temperature \({\rm{ = 273 K}}\) and pressure \( = {\rm{ }}1\) bar.
4. What is nitrogen formula?
Ans: The atomicity of nitrogen is \(2\) as it forms a triple bond with each other. Accordingly, the formula of Nitrogen is \({{\rm{N}}_{\rm{2}}}\) which is a diatomic molecule.
5. What is nitrogen cycle?
Ans: The nitrogen cycle is a biogeochemical process through which Nitrogen passes and gets converted to a variety of forms, Nitrogen moves from soil to plant to animal and then back to soil and atmosphere in different consecutive processes.
6. Where is Nitrogen found?
Ans: Nitrogen is a chemical element with a symbol of \({\rm{N}}\) with an atomic number of \(7\) and an atomic mass of \(14.007u\). Nitrogen is present on Earth in abundance, as \(78\) per cent of the atmospheric gas is Nitrogen only; the rest is oxygen gas, around \(21\) per cent with traces of some other gases.
7. Is Nitrogen harmful to humans?
Ans: Nitrogen is a very unreactive or inert gas and hence is non-toxic. So, it is said that Nitrogen is not harmful to humans or animals. But inhaling a high quantity of Nitrogen may cause uremia which shows symptoms like unconsciousness, fatigue and confusion as Nitrogen will replace the oxygen and consequently may lead to some casualties.
8. What does Nitrogen do for plants?
Ans: Nitrogen is an essential nutrient for plants to synthesise nucleic acid, proteins, chlorophyll, and enzymes of plants. Hence, Nitrogen is a primary nutrient required for plant growth.

Now that you are provided with all the necessary information on the Nitrogen and we hope this article on the Nitrogen has helped you. If you have any questions feel to post your comment below. We will get back to you at the earliest.

Practice Nitrogen Questions with Hints & Solutions