Written by the Fiveable Content Team • Last updated September 2025
Verified for the 2026 exam
Verified for the 2026 exam•Written by the Fiveable Content Team • Last updated September 2025
Definition
Nitrogen dioxide is a reddish-brown gas that forms when nitrogen oxide reacts with oxygen in the atmosphere. It is primarily released from vehicle emissions and industrial processes and contributes to smog formation.
A type of air pollution characterized by a mixture of smoke and fog. It often occurs in urban areas with high levels of pollutants like nitrogen dioxide.
Acid rain: Rainfall that has become acidic due to atmospheric pollution containing sulfur dioxide and nitrogen oxides. It can harm ecosystems by damaging plants, aquatic life, and buildings.
Photochemical reactions: Chemical reactions that occur in the presence of sunlight. Nitrogen dioxide is involved in photochemical reactions that produce ground-level ozone, a harmful pollutant.