Light bulbs are a big upgrade from fires and candles. Every year, homes in informal settlements burn down in Africa because of fires used for heating and lighting. So electrical light bulbs with filaments brought about a ...
Optics & Photonics
Nov 8, 2021
11
316
A team of researchers from Plex Corporation, Bruker Scientific LLC and Harvard University has found evidence of a protein inside of a meteorite. They have written a paper describing their findings and have uploaded it to ...
Sunscreen that includes zinc oxide, a common ingredient, loses much of its effectiveness and becomes toxic after two hours of exposure to ultraviolet radiation, according to a collaboration that included Oregon State University ...
Materials Science
Oct 14, 2021
3
4088
Caltech microbiologists have discovered bacteria that feed on manganese and use the metal as their source of calories. Such microbes were predicted to exist over a century ago, but none had been found or described until now.
Materials Science
Jul 15, 2020
3
5919
Scientists who scanned the skies above dozens of U.S. cities have made a surprising discovery about the smog that's suspended over Los Angeles: one of its key ingredients isn't disappearing as fast as it once did.
Environment
Nov 15, 2019
9
540
A team of researchers from the Instituto de Carboquímica of the Spanish National Research Council (CSIC) has made a remarkable step forward in the development of efficient and sustainable electronic devices. They have found ...
Nanomaterials
Jul 20, 2023
0
459
Viruses can spread not only via droplets or aerosols like the new coronavirus, but in water, too. In fact, some potentially dangerous pathogens of gastrointestinal diseases are water-borne viruses.
Bio & Medicine
Jun 3, 2021
0
954
Scientists at UC Riverside are suggesting something is missing from the typical roster of chemicals that astrobiologists use to search for life on planets around other stars—laughing gas.
Astrobiology
Oct 4, 2022
1
1045
Material scientists have developed a fast method for producing epsilon iron oxide and demonstrated its promise for next-generation communications devices. Its outstanding magnetic properties make it one of the most coveted ...
Nanophysics
Jun 28, 2021
1
1631
Most people are familiar with uranium as a fuel for nuclear power plants. And while that's the most common application, this element is also used in many other fields, such as dyes, medical devices, and weapons. Scientists ...
Materials Science
Aug 14, 2020
0
3007
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
