Final answer:
Ozone is a pollutant in the troposphere, causing health risks and environmental damage as a component of smog, but serves as a protective layer in the stratosphere, absorbing harmful UV radiation.
Step-by-step explanation:
The original question asks if ozone (O₃) is a pollutant in the troposphere but a protector in the stratosphere, which is true. Ozone is indeed composed of three atoms of oxygen and its behavior differs greatly depending on its location in the Earth's atmosphere. In the stratosphere, which ranges from about 10 to 50 kilometers above the Earth's surface, ozone forms naturally due to the action of ultraviolet light from the sun on molecular oxygen (O₂). This beneficial layer of ozone absorbs and protects life on Earth from harmful ultraviolet (UV) radiation.
Contrarily, ground-level ozone, often referred to as tropospheric ozone, is an air pollutant mainly generated by industrial and vehicular emissions in the presence of sunlight, contributing to the formation of smog and posing risks to human health and environmental integrity.