__________, a form of air pollution, is caused by chemical reactions between exhaust emissions and sunlight.

Smog

A type of air pollution, typically a mixture of smoke and fog, that can have harmful effects on health and the environment.

Air Pollution

The presence of harmful or excessive quantities of substances including gases, particles, and biological molecules in Earth's atmosphere which can cause disease, death to humans, damage to other living organisms such as food crops, or the natural or built environment.

Chemical Reactions

Processes in which substances interact to form new products, involving changes in molecular structure and energy.