isotope


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isotope

 [i´so-tōp]
a chemical element having the same atomic number as another (i.e., the same number of nuclear protons), but having a different atomic mass (i.e., a different number of nuclear neutrons).
radioactive isotope radioisotope.
stable isotope one that does not transmute into another element with emission of corpuscular or electromagnetic radiations.
Miller-Keane Encyclopedia and Dictionary of Medicine, Nursing, and Allied Health, Seventh Edition. © 2003 by Saunders, an imprint of Elsevier, Inc. All rights reserved.

i·so·tope

(ī'sō-tōp), An isotope is identified by its symbol preceded by a superscript numeral showing its mass number (12C). Alternatively the mass number may follow the symbol at the same level (C 12). When the name of the element rather than its symbol is used, the numeral must follow and not precede the name (carbon 12). Do not join the numeral to the symbol or the name with a hyphen. The atomic number of an element (the unvarying number of protons in its nucleus) may be shown by a subscript numeral preceding the symbol 6C).
One of two or more nuclides that are chemically identical, having the same number of protons, yet differ in mass number, because their nuclei contain different numbers of neutrons; individual isotopes are names with the inclusion of their mass number in the superscript position (12C) and the atomic number (nuclear protons in the subscript position (6C). In former usage, the mass numbers follow the chemical symbol (C-12).
[iso- + G. topos, part, place]
Farlex Partner Medical Dictionary © Farlex 2012

isotope

Imaging
An MRI term for atomic nuclei that contain the same number of protons, but differ in the number of neutrons in the nucleus of the atom for the element concerned.
Segen's Medical Dictionary. © 2012 Farlex, Inc. All rights reserved.

i·so·tope

(ī'sŏ-tōp)
One of two or more nuclides that are chemically identical, having the same number of protons, yet differ in mass number, because their nuclei contain different numbers of neutrons; individual isotopes are named with the inclusion of their mass number in the superior position (12C) and the atomic number (nuclear protons) in the inferior position (6C).
[iso- + G. topos, part, place]
Medical Dictionary for the Health Professions and Nursing © Farlex 2012

isotope

Chemically identical elements whose atomic nuclei have the same number of protons but different numbers of neutrons. The number of protons determines the number of orbital electrons and hence the chemical properties. Radioactive isotopes are called radionuclides. From the Greek iso -, equal and topos , place. Isotopes occupy the same place in the Periodic table of the elements.
Collins Dictionary of Medicine © Robert M. Youngson 2004, 2005

isotope

any of the forms of an element having the same number of protons (atomic number) but a different number of neutrons (atomic mass). Some isotopes of an element may be radioisotopes (e.g. 12C is not radioactive while 14C is) and yet can function normally in biological material. Isotopes can thus be ‘tagged’ (using suitable detection devices such as geiger counters and autoradiography) as biochemical processes occur. See HALF-LIFE, AUTO RADIO GRAPH.
Collins Dictionary of Biology, 3rd ed. © W. G. Hale, V. A. Saunders, J. P. Margham 2005

Isotope

An unstable form of an element that gives off radiation to become stable. Elements are characterized by the number of electrons around each atom. One electron's negative charge balances the positive charge of each proton in the nucleus. To keep all those positive charges in the nucleus from repelling each other (like the same poles of magnets), neutrons are added. Only certain numbers of neutrons work. Other numbers cannot hold the nucleus together, so it splits apart, giving off ionizing radiation. Sometimes one of the split products is not stable either, so another split takes place. The process is called radioactivity.
Gale Encyclopedia of Medicine. Copyright 2008 The Gale Group, Inc. All rights reserved.

i·so·tope

(ī'sŏ-tōp)
One of two or more nuclides that are chemically identical, having the same number of protons, yet differ in mass number, because their nuclei contain different numbers of neutrons.
[iso- + G. topos, part, place]
Medical Dictionary for the Dental Professions © Farlex 2012
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Changes in breath carbon isotope composition as a potential biomarker of inflammatory acute phase response in mechanically ventilated pediatric patients.
A new method of dentine microsampling of deciduous teeth for stable isotope ratio analysis.
When lead from multiple sources is combined, the resultant isotope value will reflect the average isotope ratio of the 2 or more substances, making the exact source difficult to pinpoint.
On the basis of available reports of lead isotope ratios, possible anthropogenic sources of lead in this eagle are lead paint, zinc smelting, or leaded gasoline.
During the weathering and leaching of seafloor basalts, the leached basalts are highly depleted in Fe and have heavier Fe isotope compositions than fresh basalts [17].
Furthermore, the Fe isotope composition of Fe(III) is heavier than that of Fe(II) [68-71].
These different varieties of hydrogen, carbon, nitrogen and sulfur are called isotopes. They are a trove of forensic information that is only starting to be tapped in the 21st century.
Drug analysis is another forensic niche for isotopes, including identification of counterfeit pharmaceuticals, and its use to prove doping in sports.
These location samples represent an anticipated latitudinal gradient of [[delta].sup.2]H stable isotope values.