Nitric oxide may slow progression of COVID-19

Nitric oxide treatment can be pivotal in the world's fight against SARS-CoV-2, the coronavirus that causes COVID-19, according to a review from the George Washington University (GW). The article is published in the journal ...


How long should you fast for weight loss?

Two daily fasting diets, also known as time-restricted feeding diets, are effective for weight loss, according to a new study published by researchers from the University of Illinois at Chicago.


Pain-relief drug delivers choices for mothers in labour

Choice and control are important factors for ensuring a positive childbirth experience, yet until recently, little was known about the impact of alternative administrations of fentanyl—one of the pain relief drugs used ...


Antioxidant cocktail key to preventing Alzheimer's

Research from The University of Western Australia has found a diet rich in nutrients and antioxidants may prevent or even reverse the effects of Alzheimer's disease.

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An oxide ( /ˈɒksaɪd/) is a chemical compound that contains at least one oxygen atom in its chemical formula. Metal oxides typically contain an anion of oxygen in the oxidation state of −2.

Most of the Earth's crust consists of solid oxides. Oxides result when elements are oxidized by oxygen in air. Combustion of hydrocarbons affords the two principal oxides of carbon, carbon monoxide and carbon dioxide. Even materials that are considered to be pure elements often contain a coating of oxides. For example, aluminium foil has a thin skin of Al2O3 that protects the foil from further corrosion.

Virtually all elements burn in an atmosphere of oxygen, or an oxygen rich environment. In the presence of water and oxygen (or simply air), some elements—lithium, sodium, potassium, rubidium, caesium, strontium and barium—react rapidly, even dangerously, to give the hydroxides. In part for this reason, alkali and alkaline earth metals are not found in nature in their metallic, i.e., native, form. Caesium is so reactive with oxygen that it is used as a getter in vacuum tubes, and solutions of potassium and sodium, so called NaK are used to deoxygenate and dehydrate some organic solvents. The surface of most metals consists of oxides and hydroxides in the presence of air. A well known example is aluminium foil, which is coated with a thin film of aluminium oxide that passivates the metal, slowing further corrosion. The aluminium oxide layer can be built to greater thickness by the process of electrolytic anodising. Although solid magnesium and aluminium react slowly with oxygen at STP, they, like most metals, will burn in air, generating very high temperatures. Finely grained powders of most metals can be dangerously explosive in air. Consequently, they are often used in Solid-fuel rockets.

In dry oxygen, iron readily forms iron(II) oxide, but the formation of the hydrated ferric oxides, Fe2O3−2x(OH)x, that mainly comprise rust, typically requires oxygen and water. The production of free oxygen by photosynthetic bacteria some 3.5 billion years ago precipitated iron out of solution in the oceans as Fe2O3 in the economically important iron ore hematite.

Due to its electronegativity, oxygen forms chemical bonds with almost all elements to give the corresponding oxides. Noble metals (such as gold or platinum) resist direct chemical combination with oxygen, and substances like gold(III) oxide must be generated by indirect routes.

This text uses material from Wikipedia, licensed under CC BY-SA