Smog: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.