Final answer:
Ground-level ozone near the ground is primarily formed through chemical reactions between nitrogen oxides and volatile organic compounds in the presence of sunlight.
Step-by-step explanation:
Ground-level ozone near the ground is primarily formed through chemical reactions between nitrogen oxides (NOx) and volatile organic compounds (VOCs) in the presence of sunlight. These pollutants are emitted by sources such as automobiles, power plants, and industrial and commercial activities. The reaction occurs when NOx and VOCs chemically react in the presence of sunlight.