oxygen

Definition

Oxygen is a gas that we need to breathe. It is the most abundant gas in the air, making up about 21% of the atmosphere. Oxygen is also found in water and in many living things.

Oxygen is important for life. It is used in the process of cellular respiration, which is how cells produce energy. Oxygen is also used in the process of photosynthesis, which is how plants produce food.

How can the word be used?

Oxygen is essential for life.

Different forms of the word

Noun: A chemical element with the symbol O and atomic number 8. It is the most abundant element in the Earth's atmosphere.

Adjective: Relating to oxygen.

Etymology

The word "oxygen" comes from the Greek words "oxys" (acid) and "gen" (producer).

The word "oxygen" was first used in English in 1774 by the English chemist Joseph Priestley.

Question

Why is oxygen important?