Nitrogen, Formula, Cycle, Environmental Risks, Latest News

Q: What is the most abundant gas in Earth's atmosphere?

Nitrogen is the most abundant gas in Earth's atmosphere, making up about 78% of the air by volume.

Q: What is the Nitrogen Cycle?

The Nitrogen Cycle is a biogeochemical process that converts atmospheric nitrogen into forms usable by plants and animals, involving processes like nitrogen fixation, nitrification, assimilation, ammonification, and denitrification.

Q: Name an example of nitrogen-fixing bacteria.

Rhizobium is a well-known nitrogen-fixing bacterium that lives symbiotically in the root nodules of leguminous plants.

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Nitrogen Latest News

India, the world’s second-largest emitter of N₂O after China, faces climate risks as N₂O has 300 times the global warming potential of CO₂.

About Nitrogen

Nitrogen is the most abundant atmospheric gas, constituting ~78% of Earth’s atmosphere.
Nitrogen is vital for forming DNA, ATP (cellular energy currency), proteins, chlorophyll, and acts as a neurotransmitter via nitric oxide (NO).

Nitrogen Cycle: Natural Balancing Act

Atmospheric nitrogen (N₂) is inert and unusable by plants or animals.
Plants rely on diazotrophs (N-fixing bacteria) through symbiotic association (e.g., in legumes).
Nitrifying bacteria convert ammonia into nitrites (NO₂⁻) and then nitrates (NO₃⁻) – the form plants can absorb.
- Nitrification: Ammonia → Nitrites → Nitrates (plant-usable form).
Denitrification returns excess nitrates back to the atmosphere, maintaining the natural nitrogen cycle.

Haber-Bosch Process

Developed in the early 20th century, allowed industrial fixation of nitrogen to produce ammonia.
Uses fossil fuels, high heat and pressure, and an iron catalyst.
Enabled synthetic fertiliser revolution → contributed to Green Revolution and exponential population growth.

Environmental Risks of Excess Nitrogen (Latent Time-Bomb)

Reactive nitrogen (ammonia, nitrate, nitrous oxide) is now overproduced through chemical fertilisers.
80% of applied nitrogen is lost to the environment via leaching and emissions, causing:
- Eutrophication of water bodies → Algal blooms, Dead Zones (e.g., Gulf of Mexico).
- Soil acidification and air pollution from NOx emissions.
- Formation of ground-level ozone and acid rain.
- N₂O (Nitrous oxide) is now the third most potent greenhouse gas after CO₂ and CH₄.