Final answer:
Smog is a mixture of air pollutants that form over urban areas as a result of fossil fuel combustion. There are two main types of smog: industrial and photochemical smog. It greatly reduces visibility and poses health risks to individuals, especially those with respiratory conditions.
Step-by-step explanation:
Smog is a mixture of air pollutants that form over urban areas as a result of fossil fuel combustion. It consists of sulfur dioxide, nitrogen oxides, ozone, and particulates. Smog can greatly reduce visibility and pose health risks to individuals, especially those with respiratory conditions.
The term 'smog' is coined from the words 'smoke' and 'fog' because of the brownish haze it creates in the atmosphere. There are two main types of smog: industrial smog, which is produced by the burning of fossil fuels, and photochemical smog, which is formed when sunlight drives chemical reactions between pollutants from automobiles and atmospheric compounds.