Which of the following describes a source of ozone in the atmosphere?

• A. Combustion of fossil fuels
• B. Natural production from sunlight and high voltage discharges
• C. Pollution from industrial processes
• D. Deforestation and land usage

Answer: (B)

The correct answer highlights the fact that ozone in the atmosphere can be produced naturally through two main processes: the action of sunlight and high voltage discharges, such as lightning.

Ozone forms when ultraviolet (UV) radiation from the sun splits oxygen molecules (O₂) into individual oxygen atoms. These atoms can then react with other oxygen molecules to create ozone (O₃). This natural process is crucial in the upper atmosphere, where ozone forms the ozone layer, protecting life on Earth from harmful UV radiation. Lightning also contributes to this process by providing the energy necessary for the conversion of oxygen into ozone.

In contrast to natural production, combustion of fossil fuels and pollution from industrial processes primarily produce nitrogen oxides and volatile organic compounds, which can lead to the formation of ground-level ozone through photochemical reactions. However, these are considered sources of anthropogenic (human-made) ozone rather than natural sources. Deforestation and land usage primarily impact carbon dioxide levels and local ecosystems without directly contributing to ozone formation in the atmosphere.