* The BCS theory reproduces the isotope effect, which is the experimental observation that for a given superconducting material, the critical temperature is inversely proportional to the mass of the isotope used in the material.

The choice of isotope ordinarily has little effect on the electrical properties of a material, but does affect the frequency of lattice vibrations, this effect suggested that superconductivity be related to vibrations of the lattice.

Whenever a relative atomic mass value differs by more than 1 % from a whole number, it is due to this averaging effect resulting from significant amounts of more than one isotope being naturally present in the sample of the element in question.

This is an important effect in all reactors where fast neutrons from the fissile isotope can cause the fission of nearby < sup > 238 </ sup > U nuclei, which means that some small part of the < sup > 238 </ sup > U is " burned-up " in all nuclear fuels, especially in fast breeder reactors that operate with higher-energy neutrons.

In X-ray scattering, photons interact with electrical cloud so the bigger element the bigger effect but in neutron scattering, neutron interacts with nuclei and interaction depends on isotope and some light elements like deuterium show similar scattering cross section as heavy elements like Pb.

* A secondary deuterium isotope effect of slightly larger than 1 ( commonly 1-1. 5 ) is observed.

In one study the kinetic isotope effect ( KIE ) was determined for the gas phase reaction of several alkyl halides with the chlorate ion.

For example, the isotope effect is used so extensively to investigate chemical mechanisms and the use of cosmogenic isotopes and long-lived unstable isotopes in geology that it is best to consider much of isotopic chemistry as separate from nuclear chemistry.

The mechanisms of chemical reactions can be investigated by observing how the kinetics of a reaction is changed by making an isotopic modification of a substrate, known as the kinetic isotope effect.

* Isotopes: The kinetic isotope effect consists in a different reaction rate for the same molecule if it has different isotopes, usually hydrogen isotopes, because of the mass difference between hydrogen and deuterium.

The kinetic isotope effect is the difference in the rate of a chemical reaction when an atom in one of the reactants is replaced by one of its isotopes.

However, it is reported that in the case of vinyl alcohol, formation of a stabilized enol form can be accomplished by controlling the water concentration in the system and utilizing the kinetic favorability of the deuterium produced kinetic isotope effect ( k < sub > H < sup >+</ sup ></ sub >/ k < sub > D < sup >+</ sup ></ sub >

: In one study, a reaction mechanism is proposed in which in the first slow step a proton is abstracted from nitroalkane 1 to a carbanion 2 followed by protonation to a nitronate 3 and finally nucleophilic displacement of chlorine based on an experimentally observed hydrogen kinetic isotope effect of 3. 3.

The kinetic isotope effect ( KIE ) is the ratio of reaction rates of two different isotopically labeled molecules in a chemical reaction.

In such a case, the change is termed a primary isotope effect.

When the substitution is not involved in the bond that is breaking or forming, a smaller rate change, termed a secondary isotope effect is observed.

Thus, the magnitude of the kinetic isotope effect can be used to elucidate the reaction mechanism.

This masking of the intrinsic isotope effect has been referred to as ' kinetic complexity '.

The kinetic isotope effect leads to a specific distribution of deuterium isotopes in natural products, depending on the route they were synthesized in nature.

The secondary kinetic isotope effect ( SKIE ) arises in cases where the isotopic substitution is remote from the bond being broken.

Thus, the use of the term " electronic isotope effect " while legitimate is discouraged from use as it can be misinterpreted to suggest that the isotope effect is electronic in nature rather than vibrational.

Further separation was carried out by ion exchange, yielding a certain isotope of curium.

The second isotope < sup > 242 </ sup > Am was produced upon neutron bombardment of the already-created < sup > 241 </ sup > Am.

The term isotope was coined by Margaret Todd as a suitable name for different atoms that belong to the same element.

This reaction was studied for the first time in 2007 by the team at LBNL to search for the lightest bohrium isotope < sup > 260 </ sup > Bh.

The first proposed catalytic cycle for the conversion of hydrogen into helium was at first simply called the carbon – nitrogen cycle ( CN cycle ), also honorarily referred to as the Bethe – Weizsäcker cycle, because it does not involve a stable isotope of oxygen.

Einsteinium is the element with the highest atomic number which has been observed in macroscopic quantities in its pure form, and this was the common short-lived isotope einsteinium-253.

" The investigations at Bristol, applying isotope tests on tooth enamel, checked whether she was born and brought up in Wessex and Mercia, as written history has indicated.

That is the time when I left Columbia University, and after a few months of commuting between Chicago and New York, eventually moved to Chicago to keep up the work there, and from then on, with a few notable exceptions, the work at Columbia was concentrated on the isotope separation phase of the atomic energy project, initiated by Booth, Dunning and Urey about 1940 ".

He named this concept isotope meaning ' same place ' - the word ' isotope ' was initially suggested to him by Margaret Todd.

Hafnium was the penultimate stable isotope element to be discovered ( rhenium was identified two years later ).

The reaction was repeated at the FLNR in June 2008 and results show that the 4 atoms of the isotope < sup > 270 </ sup > Hs were detected with a yield of 9 pb.

The decay data for the recently discovered isotope was confirmed, although the alpha energy was slightly higher.

This reaction with the rare and expensive < sup > 36 </ sup > S isotope was conducted at the GSI in April – May 2008.

The reaction was repeated at the GSI in Jan-Feb 2009 in order to search for the new isotope < sup > 268 </ sup > Hs.

Retrieved on 2008-03-01 </ ref > The synthesis of the important isotope < sup > 270 </ sup > Hs was published in December 2006 by the team of scientists from the Technical University of Munich .< ref >" Doubly magic < sup > 270 </ sup > Hs ", Turler et al., GSI report, 2006.

Retrieved on 2008-03-01 </ ref > It was reported that this isotope decayed by emission of an alpha-particle with an energy of 8. 83 MeV and a projected half-life of ~ 22 s, assuming a 0 < sup >+</ sup > to 0 < sup >+</ sup > ground state decay to < sup > 266 </ sup > Sg using the Viola-Seaborg equation.

This new reaction was studied at the GSI in July – August 2006 in a search for the new isotope < sup > 268 </ sup > Hs.

Helium-3 was hypothesized to be a radioactive isotope until helions were also found in samples of natural helium, which is mostly helium-4, taken both from the terrestrial atmosphere and from natural gas wells.

The Berkeley team reported that the isotope < sup > 257 </ sup > Lr was detected in this manner, and that it decayed by emitting an 8. 6 MeV alpha particle with a half-life of about eight seconds.

This isotope was later deduced to be < sup > 258 </ sup > Lr.

The team produced < sup > 256 </ sup > Md ( half-life of 87 minutes ) when they bombarded an < sup > 253 </ sup > Es target with alpha particles ( helium nuclei ) in the Berkeley Radiation Laboratory's 60-inch cyclotron (< sup > 256 </ sup > Md was the first isotope of any element to be synthesized one atom at a time ).