Oxygen | |
| Atomic Number: | 8 |
| Abbreviation: | O |
Oxygen (chemical symbol O and atomic number 8) is a chemical element. It is a gas at room temperature.
Oxygen is very important for life on earth. The atmosphere of the earth consists of approximately 21% oxygen. Humans and animals must breathe oxygen in order to live, and plants give off oxygen. Water (H2O) is a well-known chemical compound, which consists of one oxygen atom.
Combustion, or burning, is caused by the reaction of oxygen and another element or compound.