O2molekyyleihin

O2molekyyleihin refers to molecules of oxygen. The diatomic oxygen molecule, represented by the chemical formula O₂, is a highly reactive gas that is essential for most life on Earth. It comprises two oxygen atoms joined by a double covalent bond. This molecule makes up approximately 21% of the Earth's atmosphere.

Oxygen molecules are a product of photosynthesis, a process where plants and some microorganisms use sunlight, water, and carbon dioxide to create their own food and release oxygen as a byproduct. This atmospheric oxygen is then utilized by aerobic organisms, including animals and humans, through respiration. During respiration, O₂ molecules are taken into the body and used in cellular processes to generate energy, with carbon dioxide and water as waste products.

The reactivity of O₂ molecules makes them crucial for combustion, a chemical process that involves rapid reaction between a substance with an oxidant, usually oxygen, to produce heat and light. This property is harnessed in various industrial applications, from powering engines to welding and metal cutting. However, this reactivity also contributes to processes like oxidation and corrosion, where metals react with oxygen to form rust or other oxides. O₂ molecules can also participate in the formation of ozone (O₃), another allotrope of oxygen, which plays a vital role in shielding the Earth from harmful ultraviolet radiation in the stratosphere. The study of O₂ molecules falls under the domain of chemistry and biochemistry.