Nitrogen
Definition and meaning of Nitrogen in chemistry.
![Nitrogen element card: symbol N, atomic number 7, atomic mass 14.007, electron configuration [He] 2s² 2p³, oxidation states +5 +3 -3, Nonmetal, group 15, period 2, gas at room temperature.](/assets/images/terms/nitrogen-chemical-element.webp)
Nitrogen is a chemical element with the symbol N and atomic number 7. It is a nonmetal and the lightest member of group 15.
In more detail
Group 15 of the periodic table is often called the pnictogens. Nitrogen is a very common and important element in the universe. It ranks seventh in total abundance within our Solar System.
Under standard conditions, two nitrogen atoms bond together very securely. They form N2, which is a colorless and odorless diatomic gas. Diatomic nitrogen forms about 78% of the Earth's atmosphere.
It is the most abundant uncombined element on our planet. A strong triple bond holds the two nitrogen atoms tightly together. This triple covalent bond makes the gas highly stable and mostly inert.
Breaking this bond requires a huge amount of activation energy. Biological or industrial nitrogen fixation provides this needed energy. Nitrogen fixation converts the inert gas into chemically reactive forms.
Nitrogen occurs naturally in all known living organisms on Earth. It is a primary building block of biological amino acids. These amino acids link together to make essential proteins.
Nitrogen also forms the vital nucleic acids DNA and RNA. Industrially, factories convert atmospheric nitrogen into liquid ammonia. They use a famous method called the Haber-Bosch process.
This process combines pure nitrogen gas with hydrogen gas. It uses an iron catalyst at high temperature and extreme pressure. This ammonia serves as a vital precursor chemical worldwide. Companies use it to manufacture synthetic fertilizers and powerful explosives.
Key facts
| Field | General Chemistry |
|---|---|
| Symbol | N |
| Atomic number | 7 |
| Atomic mass | 14.007 u |
| Category | Nonmetal |
| Formula | N2 |
| Molar mass | 28.014 g/mol |
| State at STP | Gas |
| Boiling point | -195.8 °C |
Liquid nitrogen is extremely cold and boils at -195.8 °C. Industrial workers use it as a cryogen for rapidly freezing food. Scientists use it to preserve delicate biological samples safely. Doctors use it in cryosurgery to freeze and remove abnormal skin tissue.
Frequently asked questions
Why is nitrogen gas unreactive?
Nitrogen gas consists of diatomic molecules. A strong triple covalent bond holds the two nitrogen atoms together. Breaking this tight bond requires a very large amount of activation energy.
What is nitrogen fixation?
Nitrogen fixation is a chemical process. It converts inert atmospheric nitrogen gas into reactive compounds like ammonia or nitrates. Plants can then easily absorb and utilize these reactive nitrogen forms to grow.
Related terms
Sources & references
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