'Neutron drip line in the Ca region from Bayesian model averaging'. 'Deep excursion beyond the proton dripline. 'The AME2016 atomic mass evaluation (II). 'The NUBASE2016 evaluation of nuclear properties' (PDF). ^ Half-life, decay mode, nuclear spin, and isotopic composition is sourced in:Īudi, G.'Standard atomic weights of the elements 2021 (IUPAC Technical Report)'. ^ Prohaska, Thomas Irrgeher, Johanna Benefield, Jacqueline et al.^ 'Standard Atomic Weights: Chlorine'.'The NUBASE2020 evaluation of nuclear properties' (PDF). Isotope separation to produce pure 37Ĭl production, but a small amount might still be produced by (n,2n) reactions involving fast neutrons. This produces a long lived radioactive product which has to be stored or disposed off. In chloride-based molten salt reactors the production of 36Ĭl by neutron capture is an inevitable consequence of using natural isotope mixtures of chlorine (i.e. 36Cl has seen use in other areas of the geological sciences, forecasts, and elements. Thus, as an event marker of 1950s water in soil and ground water, 36Cl is also useful for dating waters less than 50 years before the present. The residence time of 36Cl in the atmosphere is about 1 week. Additionally, large amounts of 36Cl were produced by neutron irradiation of seawater during atmospheric detonations of nuclear weapons between 19. The half-life of this hydrophilic nonreactive isotope makes it suitable for geologic dating in the range of 60,000 to 1 million years. 36Cl decays to either 36 S (1.9%) or to 36 Ar (98.1%), with a combined half-life of 308,000 years. In the subsurface environment, 36Cl is generated primarily as a result of neutron capture by 35Cl or muon capture by 40 Ca. 36Cl is produced in the atmosphere by spallation of 36 Ar by interactions with cosmic ray protons. Chlorine (17Cl) has 25 isotopes, ranging from 28Cl to 52Cl, and two isomers, 34mCl and 38mCl. Trace amounts of radioactive 36Cl exist in the environment, in a ratio of about 7×10 −13 to 1 with stable isotopes. The shortest-lived are proton-unbound 29Cl and 30Cl, with half-lives less than 10 picoseconds and 30 nanoseconds, respectively the half-life of 28Cl is unknown. All other isotopes have half-lives under 1 hour, many less than one second. The longest-lived radioactive isotope is 36Cl, which has a half-life of 301,000 years. There are two stable isotopes, 35Cl (75.77%) and 37Cl (24.23%), giving chlorine a standard atomic weight of 35.45. Chlorine ( 17Cl) has 25 isotopes, ranging from 28Cl to 52Cl, and two isomers, 34mCl and 38mCl.

Structure of isotopes of chlorine