The invisible gas that builds your DNA and preserves your snacks

Science · Published 30 October 2026 Swipe more like this →

In short: Nitrogen makes up about 78% of the air you breathe, yet it is nearly impossible for plants to use directly. Because of its incredibly strong triple bond, this essential building block of life must be 'fixed' into the soil before it can fuel the world's ecosystems.

Nitrogen is a colorless, odorless gas that serves as a fundamental component of all living matter, specifically forming the structures of proteins and DNA. Despite its abundance in the atmosphere, plants cannot absorb it in its gaseous form because the nitrogen-nitrogen (N-N) triple bond is extremely strong. To become biologically available, nitrogen must undergo 'fixation'—a process where it is reacted into compounds by lightning or specific types of bacteria.

In the industrial world, humans have mastered this chemistry through the Haber process to manufacture ammonia. This serves as a primary starting material for nitric acid, fertilizers, pharmaceuticals, and explosives. Beyond chemistry, nitrogen is prized for its inert properties. Because it does not easily react with other substances, it is used to create oxygen-free atmospheres for sensitive industrial processes, preventing unwanted oxidation.

It is also the preferred gas for flushing food packaging, like bags of chips, to remove oxygen and prevent spoilage. The versatility of nitrogen extends to extreme temperatures. When cooled to -196°C, it becomes a liquid used in cryogenics to preserve biological specimens like blood and tissue, or in cryotherapy to remove skin abnormalities. It also serves as a cost-effective alternative to helium in gas chromatography, a technique used to separate compounds based on volatility. Historically, it was first recognized as 'foul air' in 1772 before being named nitrogen in 1790, eventually becoming a cornerstone of modern science and industry.

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