oksygeneihin

Oksygeneihin, more commonly known as oxygen, is a chemical element with the symbol O and atomic number 8. It is a member of the chalcogen group in the periodic table. Oxygen is the third most abundant element in the universe by mass, after hydrogen and helium. At standard temperature and pressure, two atoms of oxygen form a diatomic molecule with the formula O₂, which is odorless, colorless, and tasteless. Molecular oxygen is essential for life on Earth, playing a critical role in cellular respiration for most living organisms.

In its gaseous state, oxygen makes up approximately 20.95% of Earth's atmosphere. It is also a component of water (H₂O), and it is found in many organic molecules and minerals. The discovery of oxygen is credited to Carl Wilhelm Scheele in 1772 and independently to Joseph Priestley in 1774. The name "oxygen" was coined by Antoine Lavoisier in 1777.

Oxygen is a highly reactive element, readily forming oxides with most other elements. This reactivity is harnessed in numerous industrial processes, such as combustion, welding, and the production of steel. In medicine, oxygen therapy is used to treat various respiratory conditions and other ailments. Allotropes of oxygen include ozone (O₃), which is a powerful oxidizing agent and plays a vital role in the Earth's stratosphere by absorbing ultraviolet radiation.