News tagged with isotopes
Chemical fingerprinting tracks the travels of little brown bats
They're tiny creatures with glossy, chocolate-brown hair, out-sized ears and wings. They gobble mosquitoes and other insect pests during the summer and hibernate in caves and mines when the weather turns cold. ...
May 29, 2012 |
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New finding may hold key to Gaia hypothesis of Earth as living organism
(Phys.org) -- Is Earth really a sort of giant living organism as the Gaia hypothesis predicts? A new discovery made at the University of Maryland may provide a key to answering this question. This key of sulfur ...
Space & Earth / Earth Sciences
May 15, 2012 |
3.3 / 5 (32) |
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Carnivorous plant traps worms with sticky leaves
Plants eat the darndest things. Scientists have discovered a small flowering plant living in the sandy soils of Brazil that traps nematodes, or roundworms, with sticky underground leaves -- and gobbles them ...
Jan 09, 2012 |
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Methane levels 17 times higher in water wells near hydrofracking sites
A study by Duke University researchers has found high levels of leaked methane in well water collected near shale-gas drilling and hydrofracking sites. The scientists collected and analyzed water samples from 68 private ...
May 09, 2011 |
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Neanderthals died out earlier than originally believed
(PhysOrg.com) -- According to a newly released report in The Proceedings of the National Academy of Sciences, a newly refined method of radiocarbon dating has found that Neanderthals died off much earlier than o ...
Other Sciences / Archaeology & Fossils
May 10, 2011 |
4.5 / 5 (14) |
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Paleoecologists suggest mass extinction due to huge methane release
(PhysOrg.com) -- Micha Ruhl and colleagues from the University of Copenhagen's Nordic Center for Earth Evolution have published a paper in Science where they contend that the mass extinction that occurred at the ...
Space & Earth / Earth Sciences
Jul 22, 2011 |
4.4 / 5 (21) |
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New type of nuclear fission discovered
(PhysOrg.com) -- Nuclear fission, or the splitting of a heavy nucleus, usually results in symmetrical fragments of the same mass. Physicists attribute the few known examples of fission that is asymmetric to ...
Dec 06, 2010 |
4.7 / 5 (52) |
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Test shows dinosaurs survived mass extinction by 700,000 years
University of Alberta researchers determined that a fossilized dinosaur bone found in New Mexico confounds the long established paradigm that the age of dinosaurs ended between 65.5 and 66 million years ago.
Other Sciences / Archaeology & Fossils
Jan 27, 2011 |
4.3 / 5 (16) |
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Radioactive decay rates vary with the sun's rotation: research
Radioactive decay rates, thought to be unique physical constants and counted on in such fields as medicine and anthropology, may be more variable than once thought.
Aug 31, 2010 |
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Six new isotopes of the superheavy elements discovered
(PhysOrg.com) -- A team of scientists at the U.S. Department of Energy's Lawrence Berkeley National Laboratory has detected six isotopes, never seen before, of the superheavy elements 104 through 114. Starting ...
Oct 26, 2010 |
4.8 / 5 (29) |
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Dog skull dates back 33,000 years
If you think a Chihuahua doesn't have much in common with a Rottweiler, you might be on to something.
Other Sciences / Archaeology & Fossils
Jan 23, 2012 |
4.7 / 5 (15) |
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Fruit flies can detect heavy hydrogen: study
(PhysOrg.com) -- A new study by researchers in Greece and the US has found that fruit flies can discriminate between normal and heavy hydrogen (deuterium) isotopes, which adds weight to a new theory of how ...
Feb 16, 2011 |
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Low-Budget Fusion Reactor Could Generate Energy within a Decade
(PhysOrg.com) -- Currently, most nuclear fusion power plants are large, expensive projects that will take decades to benefit from. But a startup company in Vancouver, Canada, called General Fusion is taking ...
Aug 04, 2009 |
4.5 / 5 (59) |
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Neutron analysis explains dynamics behind best thermoelectric materials
Neutron analysis of the atomic dynamics behind thermal conductivity is helping scientists at the Department of Energy's Oak Ridge National Laboratory gain a deeper understanding of how thermoelectric materials ...
Jun 06, 2011 |
5 / 5 (3) |
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Radioactive Gold Nanoparticles Destroy Prostate Tumors, Leaving Healthy Tissue Untouched
(PhysOrg.com) -- One of the promises of nanoparticles as delivery agents for cancer therapeutics is that they will attack tumors while sparing healthy tissue from the damage normally associated with today's anticancer therapies. ...
Nanotechnology / Bio & Medicine
Apr 21, 2010 |
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Isotope
Isotopes (Greek isos = "equal", tópos = "site, place") are any of the different types of atoms (nuclides) of the same chemical element, each having a different atomic mass (mass number). Isotopes of an element have nuclei with the same number of protons (the same atomic number) but different numbers of neutrons. Therefore, isotopes of the same element have different mass numbers (number of nucleons).
A nuclide is any particular atomic nucleus with a specific atomic number Z and mass number A; it is equivalently an atomic nucleus with a specific number of protons and neutrons. Collectively, all the isotopes of all the elements form the set of nuclides. The distinction between the terms isotope and nuclide has somewhat blurred, and they are often used interchangeably. If they are to be distinguished in use, isotope is better used in its original sense, when referring to several different nuclides of the same chemical element. Nuclide is a later and more generic term, and is used when referencing to only one type of nucleus, and may also be used to refer to several types of nuclei of different elements. For example, it is better to say that an element such as fluorine consists of one stable nuclide rather than that it has one stable isotope, because the latter word is usually reserved to refer to more than one nuclide. On the other hand, carbon can be correctly said to have two stable isotopes, and fluorine to have several radioactive isotopes.
Isotopes and nuclides are specified by the name of the particular element, implicitly giving the atomic number, followed by a hyphen and the mass number (e.g. helium-3, carbon-12, carbon-13, iodine-131 and uranium-238). In symbolic form, the number of nucleons is denoted as a superscripted prefix to the chemical symbol (e.g. 3He, 12C, 13C, 131I and 238U).
About 339 nuclides occur naturally on Earth, of which 256 (about 75%) are stable (or, to be careful, have never been observed to decay; this note is necessary because many "stable" isotopes are predicted to be radioactive with very long half-lives). Counting the radioactive nuclides not found in nature that have been created artificially, more than 3100 nuclides are currently known.
For more information about Isotope, read the full article at
Wikipedia.
This text uses material from Wikipedia and is available under the GNU Free Documentation License.
