Isotope chemistry. Medical search. Frequent questions

A number of radioactive isotopes of the element have also been prepared, the most widely used commercially being oxygen-15, which decays by the emission of a positron with a half life of 122 seconds. (jrank.org)
Both stable and radioactive isotopes of trace metals exist, but this article focuses on those that are stable. (wikipedia.org)
Finally, some isotopes - radioactive isotopes - aren't stable, and break down. (cosmosmagazine.com)
If we can figure out how long these radioactive isotopes take to break down, we can use the concentration of isotopes to figure out how old things are. (cosmosmagazine.com)
Because of the specificity of its uptake by the human body, radioactive isotopes of iodine can also be used to treat thyroid cancer . (wikipedia.org)
Stable isotopes of carbon (δ13C), sulfur (δ34S), oxygen (δ18O), hydrogen (δ2H), nitrogen (δ15N), and radioactive isotope of hydrogen (tritium) have been applied in combination with conventional techniques (chemical) to investigate Karachi coastal water pollution due to Layari and Malir rivers, which mainly carry the domestic and industrial wastewater of Karachi Metropolitan. (intechopen.com)
a naturally occurring radioactive isotope of thorium. (dictionary.com)
Alpha particle ( ionizing radiation ) - two neutrons and two protons bound as a single particle (a helium nucleus) that is emitted from the nucleus of certain radioactive isotopes in the process of disintegration. (cdc.gov)
Background radioactivity - radioactive elements in the natural environment including those in the crust of the earth (like radioactive potassium, uranium, and thorium isotopes) and those produced by cosmic rays. (cdc.gov)
Beta particle ( ionizing radiation ) - a charged particle emitted from the nucleus of certain unstable atomic nuclei (radioactive isotopes), having the charge and mass of an electron. (cdc.gov)
The only naturally occurring isotopes of iodine are 127I and 129I, which are stable and radioactive, respectively. (cdc.gov)

While both have three protons, one isotope has three neutrons while the other has four. (cosmosmagazine.com)
Isotopes are usually referred to with a number that adds their protons and neutrons together - so the neutron-less hydrogen is called 1 H to denote its single proton, while the heaver version is 2 H to indicate there's a neutron there as well. (cosmosmagazine.com)
In fact, no elements with an atomic number of over 83 (i.e., more than eighty-three protons) have any known isotopes that are considered to be stable! (papertrell.com)
Isotopes have the same number of protons but different number of neutrons packed into the nucleus. (chemnotcheem.com)
Isotopes are defined as atoms of the same element with the same number of protons but different number of neutrons. (chemnotcheem.com)
Carbon-12, with 6 protons and 6 neutrons, is the isotope that used to define one mole. (visionlearning.com)
Neutron crystallography is emerging as a unique and highly promising technique for structural biology because, unlike other techniques, it can probe the locations of protons (or more specifically the heavier isotope deuterium) which are paramount for understanding biochemical processes, e.g. the hydrogen-bond pattern, the charge and tautomeric states, as well as the interactions with the surrounding solvent. (lu.se)
The UNILAC accelerator at GSI delivered steadily in total 6x10^18 beam particles of the stable but rare isotope 48Ca (calcium, 20 protons). (lu.se)

We examined the natural variability of carbon and nitrogen isotopes in the symbiotic sea anemone Anemonia viridis to investigate dietary shifts (autotrophy/heterotrophy) along a natural p CO 2 gradient at the island of Vulcano, Italy. (nature.com)
This fractionation enables the use of stable nitrogen isotopes (δ 15 N) to infer trophic level, and high δ 15 N recorded in bone collagen usually indicates high-protein diets (Sponheimer et al. (springer.com)

For a more complete description of these notations, see the isotope notation section in Hydrogen isotope biogeochemistry. (wikipedia.org)
These two different types of hydrogen atoms are referred to as isotopes of one another. (cosmosmagazine.com)
For example, hydrogen has three isotopes with different relative mass, which is indicated by the number behind their name. (chemnotcheem.com)
Hydrogen-3 is the heaviest isotope, with a relative mass of 3. (chemnotcheem.com)
For example, all three isotopes of hydrogen react explosively with oxygen in a 2:1 ratio. (chemnotcheem.com)
For example, hydrogen-3 is the heaviest isotope of hydrogen as it has the most number of neutrons. (chemnotcheem.com)
This is evident in the isotopes of hydrogen, as they all have a single electron each. (chemnotcheem.com)
Kinetic Isotope Effects in Multipath VTST: Application to a Hydrogen Abstraction Reaction. (computchem.gal)
The thermal conductivities of mixtures of helium with three hydrogen isotopes are reported at 77.6 and 283.2 K. Each system exhibits a negative "excess" thermal conductivity, which, with the single exception of helium + hydrogen deuteride at 283.2 K, can be predicted from the Hirschfelder-Eucken equation in conjunction with a realistic helium-hydrogen potential function. (rsc.org)

Trace gas isotope ratios are measured using a PDZ Europa TGII interfaced to a SerCon 20-20 IRMS with SysCon electronics (Sercon Ltd., Cheshire, UK). (ugent.be)
In sediments, oceans, and rivers, distinct trace metal isotope ratios exist due to biological processes such as metal ion uptake and abiotic processes such as adsorption to particulate matter that preferentially remove certain isotopes. (wikipedia.org)
Stable isotope ratios of trace metals can be used to answer a variety of questions spanning diverse fields, including oceanography, geochemistry, biology, medicine, anthropology and astronomy. (wikipedia.org)
Analysis of stable isotope ratios from mineralised tissue has been widely used for dietary reconstruction. (springer.com)
Quantifying uranium radio-isotope ratios in riverine suspended particulate matter: Insights into natural and anthropogenic influences in the glacial-fed river system of the NE Tibetan Plateau. (bvsalud.org)
Here, we revisit a previously proposed method for quantifying Early Cenozoic deep-water carbonate chemistry, using boron to calcium ratios (B/Ca) in extinct benthic foraminifera Nuttallides truempyi (Brown et al. (lu.se)

I am seeking an isotopic composition database for carbon isotopes, since I would like to make a figure showing the different isotopic compositions of different materials. (stackexchange.com)
Researchers can learn about how much the plant breathes by checking its carbon isotopes. (cosmosmagazine.com)
This study is the first of its kind to analyse carbon, nitrogen and sulphur stable isotope data from skeletons of the eleventh-seventeenth centuries in Portugal. (springer.com)
Richards and Hedges 1999 ), especially when combined with carbon isotope data. (springer.com)
Ordinary carbon contains about 1% of C13, so ordinary oxaloacetic acid can be used to determine the first isotope effect, i.e. , the ratio k12/k13. (gla.ac.uk)
The reaction involving the heavy isotope Is a little slower than the light one, so the carbon dioxide appears to have an abnormally low C13 content and from this k12/k13 can be calculated. (gla.ac.uk)
By contrast, PETM carbonate chemistry changes of the deep ocean, a larger carbon reservoir, are largely qualitatively constrained by sedimentary calcium carbonate contents (%CaCO 3 ). (lu.se)
Furthermore, we provide multiple deep-water Ω reconstructions paired with benthic foraminiferal carbon isotopes during the PETM. (lu.se)
At two sites, deep-water Ω recovered synchronously with carbon isotopes but lagged the sedimentary %CaCO 3 rebound, indicating a slower post-PETM deep-water Ω recovery than previously thought. (lu.se)

Initial hydrochemical and isotope data demonstrate stability in water composition at most of the monitoring points. (gla.ac.uk)
Therefore, it rigorously constrains temperature without needing to know the oxygen isotope composition of water, or anything else besides carbonate). (caltech.edu)
Stable isotope composition (delta(13)C and delta(15)N) of moose (Alces alces) and caribou (Rangifer tarandus) hair from the boreal forest of Jacques-Cartier Park and Cote-Nord (Quebec) and arctic tundra of Queen Maud Gulf and Southampton Island (Nunavut) was investigated as an indicator of dietary preferences and habitat use. (nih.gov)

What is mass-independent isotope separation/fractionation? (stackexchange.com)
How can any separation/fractionation of isotopes be mass-independent, if the only difference between two isotopes is mass? (stackexchange.com)
Additionally, at high temperatures, metals ions can evaporate (and subsequently condense upon cooling), and the relative differences in isotope masses of a given heavy metal leads to fractionation during these evaporation and condensation processes. (wikipedia.org)
Additionally, isotopes can have slight variations in their solubility and other chemical and physical properties, which can also drive fractionation. (wikipedia.org)

This tag should only be applied where the effects are specifically related to variance in mass number with the same atomic number (existence of isotopes). (stackexchange.com)
The existence of isotopes explains why relative atomic masses are not whole numbers (unless they are rounded up or down). (creative-chemistry.org.uk)

Because there are so many atoms, even slight differences in the concentrations of various isotopes can be used to get new information. (cosmosmagazine.com)
Abundance is the percentage of the number of atoms of a particular isotope out of the total number of atoms in a sample of an element. (chemnotcheem.com)
Since a sample of an element is a mixture of different isotopes, its relative atomic mass (Aᵣ) is in fact the average relative mass of all the atoms in the mixture. (chemnotcheem.com)

The two sources of natural promethium are rare alpha decays of natural europium -151 (producing promethium-147) and spontaneous fission of uranium (various isotopes). (wikipedia.org)

Classic/killer/easy application for the deuterium kinetic isotope effect? (stackexchange.com)
While visiting someone's o-chem class I learned about the existence of the deuterium kinetic isotope effect. (stackexchange.com)
Here, we report a new chemical isotope labelling LC-MS analytical method for one-pot derivatization of CK bases and their glycoconjugates, based on differential benzylation labelling of the adenine skeleton of CKs with benzyl bromide and its deuterium isotope-labelled reagent. (unboundmedicine.com)

This means that, depending on evaporation and rain levels around the globe, the concentration of oxygen isotopes in the rain is slightly different. (cosmosmagazine.com)
We can use this information to draw conclusions about the climate, and climate history, in an area - all by looking at oxygen isotopes. (cosmosmagazine.com)

Since the neutron has a relative mass of 1, having more neutrons will increase the relative mass of an isotope. (chemnotcheem.com)

The methods can include a variety of mass spectrometry tools, cell culture, tissue sectioning, mathematical mass balance modelling, and isotope geochemistry. (lu.se)

Usually when one says an isotope of an element is stable, it means that it has a decay half-life that is too long to be measured by current methods. (papertrell.com)
Select an isotope to calculate its radio activity decay. (easycalculation.com)
Further analysis using speciated isotope dilution mass spectrometry revealed that the decay of Cr(VI) was accompanied by the formation of Cr(III) in the sweat model. (cdc.gov)
The isotope 288-115, seen in 22+31=53 decay chains in total by now, has a half-life of 160 milliseconds - or between 140 and 190 milliseconds accounting for statistical uncertainties. (lu.se)

For assessing the folate content in a range of Brazilian PANCs, we extended the validation of an existing stable isotope dilution assay (SIDA) for the stably 13 C-labelled 10-formyl-Pte[ 13 C 5 ]Glu (10-CHO-Pte[ 13 C 5 ]Glu). (frontiersin.org)
The cRMP meets suggested performance criteria for accuracy and precision through the use of isotope dilution, calibrator bracketing, and gravimetric measurements. (cdc.gov)

The analysis of uranium isotope ratio 235U/238U in environmental media serves as a reliable method to distinguish between natural and anthropogenic sources of uranium , playing a crucial role in assessing the extent of contamination with anthropogenic uranium and disturbances in its biogeochemical cycle . (bvsalud.org)

I am confused by the following: in Ansyln's Modern Physical Organic Chemistry, a higher vibrational frequency defines a stronger bond due to the deeper/sharper potential well (page 76). (stackexchange.com)

A complete understanding of all processes that fractionate trace metal isotopes is presently lacking, but in general, isotopes of trace metals are fractionated during various chemical and biological processes due to kinetic and equilibrium isotope effects. (wikipedia.org)
Kinetic isotope effects in the decarboxylation of oxaloacetic acid were studied at 25° in aqueous solution for the acid alone, and then in turn in the presence of the cations of the rare earth metals: yttrium, dysprosium and gadolinium, which act as catalysts through complex formation. (gla.ac.uk)
The difference between the kinetic isotope effect for the uncatalysed reaction and. (gla.ac.uk)

Trace metal stable isotope biogeochemistry is the study of the distribution and relative abundances of trace metal isotopes in order to better understand the biological, geological, and chemical processes occurring in an environment. (wikipedia.org)
In order to study trace metal stable isotope biogeochemistry, it is necessary to compare the relative abundances of isotopes of trace metals in a given biological, geological, or chemical pool to a standard (discussed individually for each isotope system below) and monitor how those relative abundances change as a result of various biogeochemical processes. (wikipedia.org)
Trace metal stable isotope biogeochemistry is still an emerging field, yet each trace metal isotope system has clear, powerful applications to diverse and important questions. (wikipedia.org)

ISOFYS provides 13 C, 15 N and 18 O isotope analysis of N 2 , N 2 O, CO 2 and CH 4 using a trace gas unit interfaced with an isotope ratio mass spectrometer (IRMS). (ugent.be)

Conventional notations used to mathematically describe isotope abundances, as exemplified here for 56Fe, include the isotope ratio (56R), fractional abundance (56F) and delta notation (δ56Fe). (wikipedia.org)
the percentage abundance of each isotope. (creative-chemistry.org.uk)

What is an isotope, and what is isotopic analysis? (cosmosmagazine.com)
If you're a keen reader of science news , you may have seen the words "isotope" or "isotopic analysis" pop up in a few wildly different articles. (cosmosmagazine.com)
Here we reconstruct continuous surface ocean pH, CO 2 , and surface ocean aragonite saturation state using boron isotopes from the planktonic foraminifer Trilobatus trilobus and we perform a sensitivity analysis of the key variables in our calculations (e.g. δ11 B sw , [Ca] sw , CCD). (news-oceanacidification-icc.org)
Chemical isotope labelling LC-MS analysis methods have been developed for most other phytohormones, enhancing their LC separations and quantitative sensitivity. (unboundmedicine.com)
Today, the capabilities of the SNS and HFIR are broad and include neutron scattering, isotope production, accelerator research, neutrino physics, materials irradiation, fundamental particle physics, gamma irradiation and materials activation analysis. (lu.se)

While their relative mass is different, isotopes are like peas in a pod in terms of chemical properties. (chemnotcheem.com)
Isotopes of the same element have different physical properties but similar chemical properties. (chemnotcheem.com)
To get to the core of why isotopes have varying mass but similar chemical properties, we have to examine their atomic structure. (chemnotcheem.com)
With the same electronic configuration, isotopes form the same type of bond and have similar chemical properties. (chemnotcheem.com)
Isotopes of an element have identical chemical properties. (creative-chemistry.org.uk)
Promethium-145 is the most stable promethium isotope, but the only isotope with practical applications is promethium-147, chemical compounds of which are used in luminous paint , atomic batteries and thickness-measurement devices. (wikipedia.org)
Okay, so maybe puns aren't part of the chemistry curriculum, but issues of matter, nuclear structure, and yes, chemical reactions certainly are. (testprepreview.com)

Furthermore, as different biogeochemical processes vary the relative abundances of the isotopes of a given trace metal, different reaction pools or substances will become enriched or depleted in specific isotopes. (wikipedia.org)
There are also some trace amounts of other isotopes of silicon). (cosmosmagazine.com)

In the past year at Cosmos alone, we've mentioned isotopes in articles on geology , astronomy , palaeontology , nuclear science , history , ecology and chemistry . (cosmosmagazine.com)
The team works at the intersection between tumor biology, evolution, chemistry, and geology. (lu.se)

Diffusion of isotopes through a solution or material can also result in fractionations, as the lighter mass isotopes are able to diffuse at a faster rate. (wikipedia.org)
On Earth, water (H 2 O) containing a lighter isotope of oxygen, for instance, evaporates better, while H 2 O with the heavier oxygen isotope tends to precipitate faster. (cosmosmagazine.com)
Lighter oxygen isotope" and "heavier oxygen isotope" aren't really precise enough terms - especially if you're working with an element that has more than two naturally occurring isotopes. (cosmosmagazine.com)

The distinctive characteristics of this location render it a unique environmental setting where the seawater chemistry varies along a p CO 2 gradient of several hundred meters moving away from the venting source. (nature.com)

13C by isotope ratio mass spectrometry. (cdc.gov)

The essence of the temperature and isotope dependence of the 1b_{1} double peaks is explained by molecular dynamics simulations including full vibrational (O─H stretching, bending, and) modes, rotational combined with the density functional theory and core-hole induced dynamics. (lu.se)

A Physical Chemistry seminar by Guest Researcher Federica Sebastiani, Physical Chemistry Lund University. (lu.se)
Henrik Nordanger, PhD student by Physical Chemistry, Lund University will defend his doctoral thesis. (lu.se)
Lecture Hall B, Department of Chemistry, Lund University. (lu.se)
The project is a collaboration between Prof. Ulf Ryde at the Division of Theoretical Chemistry, Lund University and Drs. Esko Oskanen and Thomas Rod at ESS. (lu.se)

Use of reactant-assisted analytical chemistry to quantify amounts of metal sensitizers on samples could overestimate biologically relevant exposure. (cdc.gov)

MYRRHA is an Accelerator Driven System (ADS) program at SCK CEN that includes an ISOL (Isotope Separation OnLine) facility. (sckcen.be)
The involved chemistry relies on basic knowledge of element separation involving radiochemical techniques such as liquid-liquid extraction, ion chromatography, pyrochemistry or precipitation. (psi.ch)

I have read that substitution of a bond with isotopes can alter the rate of a reaction. (stackexchange.com)
Students can have an interesting "reaction" to chemistry. (testprepreview.com)

Prior to the ILL, Paul was an Associate Laboratory Director at Oak Ridge National Laboratory with responsibility for leading the operation and development of the Spallation Neutron Source (SNS) and the High Flux Isotope Reactor (HFIR) user facilities. (lu.se)

The answer lies with chemistry - and atomic structure. (cosmosmagazine.com)

Likewise, the relative atomic mass of chlorine is 35.5 because it consists two isotopes: chlorine-35 and chlorine-37. (chemnotcheem.com)
A sample of chlorine contains two different isotopes, as shown in the table. (creative-chemistry.org.uk)

Atomic mass of Copper $=63.546amu$ Mass of $^{63}Cu = 62.9298amu$ Mass of $^{65}Cu = 64.9278amu$ Let the fraction of $^{63}Cu = x$ The fraction of $^{65}Cu = (1-x)$ The atomic mass of an element is the weighted average of the masses of the constituent isotopes. (gradesaver.com)

The target segments were manufactured the Institute of Nuclear Chemistry at the Johannes Gutenberg-University Mainz, Germany. (lu.se)

Additionally, the human samples have higher stable isotope differences, in comparison with faunal samples, than would be expected within the food web, particularly for δ 13 C. This human bone collagen δ 13 C enrichment may reflect a diet rich in aquatic protein intake, which is also supported by δ 34 S archived in human and faunal samples, and the presence of oysters and cockles shells at the excavation. (springer.com)

This differs in important waysfrom Urey's classic carbonate-water oxygen isotope thermometer (or similar ones based on other set ofs phases. (caltech.edu)

Living things also distinguish between isotopes. (cosmosmagazine.com)
When writing about isotopes, researchers tend to use numbers to distinguish them. (cosmosmagazine.com)

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