Production of animal protein in China has increased by 800% over the past 40 years, driven by population growth, urbanization and higher worker wages. However, the amount of climate-warming nitrous oxide released from animal ...
Environment
15 hours ago
1
49
Engineers rely on catalysts for a vast array of applications from food manufacturing to chemical production, so finding efficient, environmentally friendly catalysts is an important avenue of research.
Analytical Chemistry
May 18, 2022
0
121
A research group led by Prof. Xiao Jianping and Assoc. Prof. Jiao Feng from the Dalian Institute of Chemical Physics (DICP) of the Chinese Academy of Sciences (CAS), in collaboration with Prof. Qu Zhenping from Dalian University ...
Materials Science
May 13, 2022
0
30
Scientists have grown plants in soil from the Moon, a first in human history and a milestone in lunar and space exploration.
Plants & Animals
May 12, 2022
1
395
With smoggy Southern California poised to miss a critical clean air goal next year, local regulators are now threatening to sue the Environmental Protection Agency, saying the federal government has made their job "impossible."
Environment
May 11, 2022
0
7
When industrial effluents containing high levels of heavy metals are discharged into fish bodies, they pose a serious threat to aquatic ecosystems. One such heavy metal, zinc, is required by organisms in miniscule amounts, ...
Plants & Animals
May 10, 2022
0
10
The emission of greenhouse gases threatens the global environment, and scientists around the world are increasingly committed to addressing this issue. While many research groups focus on carbon dioxide (CO2) or methane (CH4) ...
Materials Science
May 09, 2022
0
230
Gradually replacing 20 percent of global beef and lamb consumption with meat-textured proteins grown in stainless steel vats could cut agriculture-related CO2 emissions and deforestation in half by 2050, researchers reported ...
Environment
May 07, 2022
3
95
Earth system scientists at the University of California, Irvine and other institutions have drawn the clearest line yet connecting consumers of agricultural produce in wealthier countries in Asia, Europe and North America ...
Environment
May 06, 2022
18
188
New materials will enable novel technologies to turn sunlight into electricity and fuels. Combinations of molecules and tiny nanoparticles make these materials a reality. The molecules in these materials are very good at ...
Nanophysics
Apr 29, 2022
0
161
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
