Related topics: atoms , protein , proceedings of the national academy of sciences , cells , genes
Molecule
hideA 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.
For more information about Molecule, read the full article at
Wikipedia.
This text uses material from Wikipedia and is available under the GNU Free Documentation License.
News tagged with molecules
Producing hydrogen from urine
Chemistry / Analytical Chemistry
Jul 03, 2009 |
4.6 / 5 (52) |
20
(PhysOrg.com) -- You do two things at motorway services: fill up one tank and empty another. US chemists have combined refuelling your car and relieving yourself by creating a new catalyst that can extract ...
Machine Converts CO2 into Gasoline, Diesel, and Jet Fuel
Nov 23, 2009 |
4.4 / 5 (45) |
25
(PhysOrg.com) -- Researchers at Sandia National Laboratories have built a machine that uses the sun's energy to convert carbon dioxide waste from power plants into transportation fuels such as gasoline, diesel, ...
Scientists Give a Hand(edness) to the Search for Alien Life
Apr 22, 2009 |
4.8 / 5 (31) |
10
(PhysOrg.com) -- Visiting aliens may be the stuff of legend, but if a scientific team working at the National Institute of Standards and Technology is right, we may be able to find extraterrestrial life even ...
India's 'holy powder' finally reveals its centuries-old secret
Chemistry / Analytical Chemistry
Apr 20, 2009 |
4.7 / 5 (31) |
3
Scientists in Michigan are reporting discovery of the secret behind the fabled healing power of the main ingredient in turmeric — a spice revered in India as "holy powder." Their study on the ingredient, curcumin, ...
Innovation puts next-generation solar cells on the horizon
Dec 01, 2009 |
4.3 / 5 (30) |
12
In a world first, a Monash University-led international research team has developed an innovative way to boost the output of the next generation of solar cells.
Buffer gas cooling could open up the field of ultracold physics
Sep 17, 2009 |
4.8 / 5 (23) |
2
(PhysOrg.com) -- "Scientists have been making Bose-Einstein Condensates [BECs] for nearly 15 years," Charlie Doret tells PhysOrg.com. "Essentially all BEC research to date, however, begins with laser cooling. Unfortunately, ...
Caltech scientists film photons with electrons
Dec 16, 2009 |
4.9 / 5 (21) |
0
(PhysOrg.com) -- Techniques recently invented by researchers at the California Institute of Technology -- which allow the real-time, real-space visualization of fleeting changes in the structure of nanoscale ...
Faster, cheaper DNA sequencing method developed
Nanotechnology / Bio & Medicine
Dec 20, 2009 |
4.4 / 5 (22) |
10
(PhysOrg.com) -- Boston University biomedical engineers have devised a method for making future genome sequencing faster and cheaper by dramatically reducing the amount of DNA required, thus eliminating the ...
Team reports major step forward in cell reprogramming
Oct 08, 2009 |
4.9 / 5 (18) |
0
(PhysOrg.com) -- A team of Harvard Stem Cell Institute (HSCI) researchers has made a major advance toward producing induced pluripotent stem cells, or iPS cells, that are safe enough to use in treating diseases ...
A Mars Rover Named 'Curiosity'
Space & Earth / Space Exploration
Oct 30, 2009 |
4.9 / 5 (18) |
2
(PhysOrg.com) -- If you found your grandmother's diary, tattered and dust covered, up in the attic, would you read it? Of course you would. Granny was a pistol! Brush off the dust, open up the little book, ...
Darwin in a test tube: Scientists make molecules that evolve, compete, mimick behavior of Darwin's finches
Apr 29, 2009 |
4.7 / 5 (18) |
6
As described in an article published this week in an advance, online edition of the journal Proceedings of the National Academy of Sciences (PNAS), the work demonstrates some of the classic principles of evolution. For in ...
Researcher discover two highly complex organic molecules detected in space
Apr 21, 2009 |
4.8 / 5 (16) |
10
(PhysOrg.com) -- Scientists from the Max Planck Institute for Radio Astronomy (MPIfR) in Bonn, Germany, Cornell University, USA, and the University of Cologne, Germany, have detected two of the most complex ...
Scientists isolate new antifreeze molecule in Alaska beetle
Dec 14, 2009 |
5 / 5 (14) |
4
Scientists have identified a novel antifreeze molecule in a freeze-tolerant Alaska beetle able to survive temperatures below minus 100 degrees Fahrenheit. Unlike all previously described biological antifreezes that contain ...
Rethinking Brownian motion with the 'Emperor's New Clothes'
Jul 27, 2009 |
4.6 / 5 (15) |
10
In the classic fairy tale, "The Emperor's New Clothes," Hans Christian Andersen uses the eyes of a child to challenge conventional wisdom and help others to see more clearly. In similar fashion, researchers at the University ...
A new day dawned fast: Recovery from marine mass extinction happened much faster than thought
Space & Earth / Earth Sciences
Oct 02, 2009 |
4.8 / 5 (14) |
0
(PhysOrg.com) -- In 1979, Luis Alvarez and his collaborators stunned the world with their discovery that an asteroid impact 65 million years ago probably killed off the dinosaurs and much of the the world's ...
