What is Oxidation?
Oxidation a Chemical ReactionOxidation is a chemical reaction that takes place when a substance is exposed to oxygen. During the process its chemical composition changes.
The term oxidisation may also be used.
The process can be seen when an apple is peeled but not eaten. Oxidation takes place in many foods after being exposed to oxygen. The reaction causes their chemical composition to break down. Antioxidants which can be natural or man-made slow down the process of oxidation or prevent it from happening.
As food oxidises it loses nutritional value.
In minerals oxidation takes place through weathering. Weathering is a process that changes the landscape of Earth. It slowly breaks down rocks and minerals through natural elements. These can be water, ice, acids, salts, plants, animals and changes in temperature.
Oxygen slowly destroys old compounds. Oxide minerals are produced when iron combines with oxygen. Rust is a common iron oxide. When minerals oxidise they become less resistant to weathering.
The distinctive black markings in rhodonite are caused through the oxidation of manganese oxides. These form as a crust on the surface of the mineral.