News tagged with hydrogen bonds
Scientists investigate how ice melts below freezing due to nanowire's pressure
(PhysOrg.com) -- The many ways in which water differs from other molecules is both a scientific curiosity and an important factor in shaping the Earth. Among water's unique properties are that it expands when ...
Sep 02, 2010 |
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Water still has a few secrets to tell
(PhysOrg.com) -- We are used to thinking of water as a substance with relatively few secrets left. Its basic structure has been studied by high school students for decades, and water is considered essential ...
Jan 21, 2010 |
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Why Does Water Expand When it Cools? A New Explanation
(PhysOrg.com) -- Most of us, when we take our first science classes, learn that when things cool down, they shrink. (When they heat up, we learn, they usually expand.) However, water seems to be the exception ...
Jul 17, 2009 |
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Probing hydrogen under extreme conditions
(Phys.org) -- How hydrogen--the most abundant element in the cosmos--responds to extremes of pressure and temperature is one of the major challenges in modern physical science. Moreover, knowledge gleaned ...
Apr 13, 2012 |
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Two-step technique makes graphene suitable for organic chemistry
The future brightened for organic chemistry when researchers at Rice University found a highly controllable way to attach organic molecules to pristine graphene, making the miracle material suitable for a ...
Nanotechnology / Nanomaterials
Nov 29, 2011 |
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Research: Graphene grows better on certain copper crystals
New observations could improve industrial production of high-quality graphene, hastening the era of graphene-based consumer electronics, thanks to University of Illinois engineers.
Nanotechnology / Nanomaterials
Oct 27, 2011 |
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Long-standing plant biochemistry mystery solved
Scientists at the U.S. Department of Energy's (DOE) Brookhaven National Laboratory and collaborators at the Karolinska Institute in Sweden have discovered how an enzyme "knows" where to insert a double bond ...
Sep 19, 2011 |
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Novel alloy could produce hydrogen fuel from sunlight
Scientists from the University of Kentucky and the University of Louisville have determined that an inexpensive semiconductor material can be "tweaked" to generate hydrogen from water using sunlight.
Aug 30, 2011 |
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Disorder is key to nanotube mystery
Scientists often find strange and unexpected things when they look at materials at the nanoscale -- the level of single atoms and molecules. This holds true even for the most common materials, such as water.
Nanotechnology / Nanomaterials
Aug 12, 2011 |
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Inexpensive catalyst that makes hydrogen gas 10 times faster than natural enzyme
Looking to nature for their muse, researchers have used a common protein to guide the design of a material that can make energy-storing hydrogen gas. The synthetic material works 10 times faster than the original ...
Aug 11, 2011 |
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Chemists create molecular polyhedron
Chemists have created a molecular polyhedron, a ground-breaking assembly that has the potential to impact a range of industrial and consumer products, including magnetic and optical materials.
Jul 21, 2011 |
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Water Motions Revealed (w/ Video)
(PhysOrg.com) -- Gaze into a glass of water, and you're unlikely to see much more than your own reflection. But gaze a little deeper using a microscope -- or, better yet, a series of laser pulses and detectors ...
May 21, 2010 |
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IBM demonstrates nonoscale 3D patterning technique (w/ Video)
(PhysOrg.com) -- IBM Research in Zurich has demonstrated a new nanoscale patterning technique that could replace electron beam lithography (EBL). The demonstration carved a 1:5 billion scale three-dimensional ...
Apr 23, 2010 |
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New analysis of the structure of spider silks explains paradox of super-strength
Spiders and silkworms are masters of materials science, but scientists are finally catching up. Silks are among the toughest materials known, stronger and less brittle, pound for pound, than steel. Now scientists ...
Nanotechnology / Nanomaterials
Mar 14, 2010 |
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Golden pairs: Catalytic dimers of gold atoms make ethylene from methane
(PhysOrg.com) -- Ethylene (ethene, CH2=CH2) is a primary feedstock for chemical industry, and particularly for the production of plastics like polyethylene and polystyrene. Ethylene is currently made by the steam cracking ...
Jan 19, 2010 |
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Hydrogen bond
A hydrogen bond is the attractive interaction of a hydrogen atom with an electronegative atom, like nitrogen, oxygen or fluorine (thus the name "hydrogen bond", which must not be confused with a covalent bond to hydrogen). The hydrogen is covalently bonded to another electronegative atom. The energy of a hydrogen bond (typically 5 to 30 kJ/mole) is comparable to that of weak covalent bonds (155 kJ/mol), and a typical covalent bond is only 20 times stronger than an intermolecular hydrogen bond. These bonds can occur between molecules (intermolecularly), or within different parts of a single molecule (intramolecularly). The hydrogen bond is stronger than a van der Waals interaction, but weaker than covalent, or ionic bonds. This type of bond occurs in both inorganic molecules such as water and organic molecules such as DNA.
Intermolecular hydrogen bonding is responsible for the high boiling point of water (100 °C). This is because of the strong hydrogen bond, as opposed to other group 16 hydrides. Intramolecular hydrogen bonding is partly responsible for the secondary, tertiary, and quaternary structures of proteins and nucleic acids.
For more information about Hydrogen bond, read the full article at
Wikipedia.
This text uses material from Wikipedia and is available under the GNU Free Documentation License.
