Oxygen is a vital element for life on Earth, making up about 21% of the atmosphere. It is essential for respiration in most living organisms, including humans, as it helps convert food into energy. Oxygen is also a key player in combustion, allowing fires to burn and fuels to release energy. In its pure form, oxygen is a colorless, odorless gas. It exists as a diatomic molecule, represented as O2. This element is crucial for various industrial processes, including steel manufacturing and water treatment. Additionally, oxygen supports aquatic life, as it dissolves in water, enabling fish and other organisms to breathe.