What does oxygen do in the atmosphere?

Oxygen in the atmosphere is essential for supporting life, as it is a key component of cellular respiration in most living organisms, allowing them to convert food into energy. It also plays a crucial role in various chemical processes, including combustion and the formation of ozone, which protects the Earth from harmful ultraviolet radiation. Additionally, oxygen contributes to the overall balance of gases in the atmosphere, helping to sustain ecosystems and regulate climate.