Energy & Green Tech
A team of engineers at the University of Massachusetts Amherst has recently shown that nearly any material can be turned into a device that continuously harvests electricity from humidity in the air. The secret lies in being ...
May 24, 2023
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1590
Machine learning & AI
Artificial intelligence can be used to predict molecular wave functions and the electronic properties of molecules. This innovative AI method developed by a team of researchers at the University of Warwick, the Technical ...
Nov 18, 2019
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11820
Engineering
It happens far too often: you plug your laptop in and walk away only to return hours or days later to find it has lost some of its charge despite sitting idle and unused.
Jan 17, 2023
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525
Energy & Green Tech
Over the past few years, engineers have created increasingly advanced technologies to produce and store energy more sustainably. Solar cells made of organic molecules or polymers are among the most promising sustainable energy ...
Energy & Green Tech
Proton exchange membrane fuel cells (PEMFCs) are power cells that can transform the chemical energy produced during the electrochemical reaction between hydrogen and oxygen into electrical energy. While these cells could ...
Energy & Green Tech
(Phys.org) —You heard it last month, last week and most probably will hear the same message tomorrow: battery-bothered ordinary citizens wish that the best and brightest in labs could just take their hands off the next ...
Energy & Green Tech
A scientific breakthrough brings mass production of the next generation of cheaper and lighter perovskite solar cells one step closer thanks to researchers at the University of Surrey's Advanced Technology Institute (ATI). ...
Sep 20, 2023
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122
Computer Sciences
Computer scientists at University of California, Davis, Maynooth University in Ireland and the California Institute of Technology have created DNA molecules that can self-assemble into patterns essentially by running their ...
Mar 20, 2019
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1728
Engineering
(Tech Xplore)—A team of researchers from the U.S. and China has demonstrated electronic devices that can degrade and disappear on demand using nothing but moisture in the air. In their paper published on the open access ...
Energy & Green Tech
How can we store solar energy for period when the sun doesn't shine? One solution is to convert it into hydrogen through water electrolysis. The idea is to use the electrical current produced by a solar panel to 'split' water ...
Aug 25, 2016
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3165
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
