Energy & Green Tech
Organic solar cells are photovoltaic technologies with light-absorbing layers made of conductive organic polymers or organic molecules. These solar energy solutions can have notable advantages over their non-organic counterparts, ...
Engineering
An explanation for why flow batteries using the metal cerium in a sulfuric acid electrolyte fall short on voltage, discovered through a study led by the University of Michigan, could pave the way for better battery chemistry.
Nov 15, 2022
0
89
Energy & Green Tech
As the world's demand for energy increases, the need for better energy storage devices becomes even greater. One way to address this, and to think about sustainability at the same time, is to turn to organic materials for ...
Nov 10, 2022
0
4
Energy & Green Tech
Arid and surrounded by the salt waters of the Persian Gulf, World Cup host Qatar is among the world's most water-stressed countries. The nation of 2.9 million people has no rivers, and receives less than four inches (10 centimeters) ...
Nov 10, 2022
0
10
Energy & Green Tech
Researchers from the University of Twente, in collaboration with Shell, developed a new mechanism that makes the conversion of carbon dioxide into carbon monoxide, which is an essential feedstock in the production of chemicals.
Nov 8, 2022
0
392
Machine learning & AI
By combining machine learning with the laws of physics, researchers in the lab of Matthew Lew, associate professor of electrical and systems engineering at Washington University in St. Louis, have been able to sort out the ...
Nov 2, 2022
0
248
Electronics & Semiconductors
Field-effect transistors (FETs) are transistors in which the resistance of most of the electrical current can be controlled by a transverse electric field. Over the past decade or so, these devices have proved to be very ...
Energy & Green Tech
NIMS has developed a durable 1-cm2 perovskite solar cell capable of generating electricity for more than 1,000 continuous hours at a photoelectric conversion efficiency (i.e., power generation efficiency) of more than 20% ...
Oct 7, 2022
0
392
Business
A material 3M has been working on for decades could be key to unlocking cost-effective production of green hydrogen, a promising but expensive renewable fuel source.
Oct 5, 2022
0
12
Energy & Green Tech
Modern societies are still very much dependent on oil and gas resources for their smooth functioning. However, natural oil and gas resources are limited and non-renewable. In order to keep up with the growing demand for hydrocarbons, ...
Sep 8, 2022
0
7
A molecule is defined as a sufficiently stable, electrically neutral group of at least two atoms in a definite arrangement held together by very strong (covalent) chemical bonds. Molecules are distinguished from polyatomic ions in this strict sense. In organic chemistry and biochemistry, the term molecule is used less strictly and also is applied to charged organic molecules and biomolecules.
In the kinetic theory of gases the term molecule is often used for any gaseous particle regardless of its composition. According to this definition noble gas atoms are considered molecules despite the fact that they are composed of a single non-bonded atom.
A molecule may consist of atoms of a single chemical element, as with oxygen (O2), or of different elements, as with water (H2O). Atoms and complexes connected by non-covalent bonds such as hydrogen bonds or ionic bonds are generally not considered single molecules.
No typical molecule can be defined for ionic crystals (salts) and covalent crystals (network solids), although these are often composed of repeating unit cells that extend either in a plane (such as in graphene) or three-dimensionally (such as in diamond or sodium chloride). The theme of repeated unit-cellular-structure also holds for most condensed phases with metallic bonding. In glasses (solids that exist in a vitreous disordered state), atoms may also be held together by chemical bonds without any definable molecule, but also without any of the regularity of repeating units that characterises crystals.
This text uses material from Wikipedia, licensed under CC BY-SA
