Oxygen (O)

Definition

Oxygen is a chemical element with symbol O and atomic number 8. It's essential for life on Earth because it's part of water molecules and used by cells for respiration process.

Related terms

Oxidation Reaction: A reaction where atoms lose electrons or gain oxygen atoms.

Respiration:

A metabolic process that uses oxygen to generate ATP by breaking down glucose.

Ozone (O3): A molecule composed of three oxygen atoms, found in the Earth's upper atmosphere and protects us from harmful ultraviolet radiation.