How to clean up New Delhi's smoggy air
An international study led by atmospheric researchers at PSI shows for the first time what portions of particulates in the air over northern India are especially harmful to health.
An international study led by atmospheric researchers at PSI shows for the first time what portions of particulates in the air over northern India are especially harmful to health.
Environment
5 hours ago
0
1
In the relentless battle against airborne viruses, researchers have developed a new spray coating to improve the antiviral efficacy of personal protective equipment, notably face masks. The study is published in the journal ...
Bio & Medicine
Apr 22, 2024
0
20
Human mini-lungs grown by University of Manchester scientists can mimic the response of animals when exposed to certain nanomaterials. The study is published in Nano Today.
Bio & Medicine
Apr 18, 2024
0
44
While it may not look like it, the interstellar space between stars is far from empty. Atoms, ions, molecules, and more reside in this ethereal environment known as the Interstellar Medium (ISM). The ISM has fascinated scientists ...
Analytical Chemistry
Apr 17, 2024
0
56
Perovskites are among the most extensively studied materials in modern materials science. Their often unique and exotic properties, which stem from perovskite's peculiar crystal structure, could find revolutionary applications ...
Analytical Chemistry
Apr 17, 2024
0
2
Increasing atmospheric concentrations of greenhouse gases (GHGs) are having irreversible consequences for the future of the Earth. However, the general pattern of the impacts of ecological restoration on the three major GHGs ...
Environment
Apr 16, 2024
0
44
Insect pheromones are odor molecules used for chemical communication within a species. Sex pheromones play a crucial role in the mating of many insects. Species-specific odors attract males and females of the same species. ...
Ecology
Apr 11, 2024
0
2
Fuel cells are quickly becoming a viable, clean energy alternative to commonly used fossil fuels, such as gasoline, coal, and oil. Fossil fuels are non-renewable energy resources that release carbon dioxide into the atmosphere.
Analytical Chemistry
Apr 10, 2024
0
50
Sunlight has a major influence on chemical processes. Its high-energy UV radiation in particular is strongly absorbed by all materials and triggers photochemical reactions of the substances present in the air. A well-known ...
Optics & Photonics
Apr 10, 2024
0
31
Mitochondria, organelles with an inner and outer membrane, are responsible for creating the energy that cells use to survive, and their morphology is key to accomplishing this task. The inner mitochondrial membrane contains ...
Molecular & Computational biology
Apr 8, 2024
0
74
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