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The alkaline earth metal strontium (38 Sr) has four stable, naturally occurring isotopes: 84 Sr (0.56%), 86 Sr (9.86%), 87 Sr (7.0%) and 88 Sr (82.58%). Its standard atomic weight is 87.62(1). Only 87 Sr is radiogenic ; it is produced by decay from the radioactive alkali metal 87 Rb , which has a half-life of 4.88 × 10 10 years (i.e. more than ...
Natural strontium is a mixture of four stable isotopes: 84 Sr, 86 Sr, 87 Sr, and 88 Sr. [11] On these isotopes, 88 Sr is the most abundant, makes up about 82.6% of all natural strontium, though the abundance varies due to the production of radiogenic 87 Sr as the daughter of long-lived beta-decaying 87 Rb. [22]
Rb–Sr dating relies on correctly measuring the Rb–Sr ratio of a mineral or whole rock sample, plus deriving an accurate 87 Sr/ 86 Sr ratio for the mineral or whole rock sample. Several preconditions must be satisfied before a Rb–Sr date can be considered as representing the time of emplacement or formation of a rock.
They considered elements 158 through 164 to be homologues of groups 4 through 10, and not 6 through 12, noting similarities of electron configurations to the period 5 transition metals (e.g. element 159 7d 4 9s 1 vs Nb 4d 4 5s 1, element 160 7d 5 9s 1 vs Mo 4d 5 5s 1, element 162 7d 7 9s 1 vs Ru 4d 7 5s 1, element 163 7d 8 9s 1 vs Rh 4d 8 5s 1 ...
Naturally occurring strontium is nonradioactive and nontoxic at levels normally found in the environment, but 90 Sr is a radiation hazard. [4] 90 Sr undergoes β − decay with a half-life of 28.79 years and a decay energy of 0.546 MeV distributed to an electron, an antineutrino, and the yttrium isotope 90 Y, which in turn undergoes β − decay with a half-life of 64 hours and a decay energy ...
Rubidium-87 was the first and the most popular atom for making Bose–Einstein condensates in dilute atomic gases.Even though rubidium-85 is more abundant, rubidium-87 has a positive scattering length, which means it is mutually repulsive, at low temperatures.
38 Si 25 37 Mg 38 Al 39 Si 26 37 Na 38 Mg 39 Al 40 Si 27 40 Al 41 Si 28 39 Na 40 Mg ... 84 Sr 85 Y 86 Zr 87 Nb 88 Mo 89 Tc 90 Ru 47 77 Zn. 78 Ga 79 Ge. 80 As 81 Se ...
Krypton-85 (85 Kr) is a radioisotope of krypton.. Krypton-85 has a half-life of 10.756 years and a maximum decay energy of 687 keV. [1] It decays into stable rubidium-85.Its most common decay (99.57%) is by beta particle emission with a maximum energy of 687 keV and an average energy of 251 keV.