Cesium 133



IsotopeAtomic mass (Da)Isotopic abundance (amount fraction)
133Cs 132.905 451 96(6)1

Cesium-133 is naturally occuring and is stable(2). Cesium-112 through 132 and 134 through 148 are artificially produced and are radioactive(2). CRC Handbook of Chemistry and Physics 86th Edition 2005-2006, Chart of the nuclides /and/ information booklet 16th ed.


Cesium 133 Half Life

  • Cesium (Cs, atomic number 55, in group 1 of the periodic table of elements, standard atomic weight 132.9, density 1.9 g/cm 3, occurring as Ce + in chemical compounds) has 40 known isotopes with atomic masses from 112 to 151. Only 133 Cs is stable.
  • Here was have something else entirely, the Bathys Cesium 133, which actually contains a microchip housing a tiny atomic clock in the watch itself. This is a world first, and while the Cesium 133 is still in prototype stages, the makers are selling the first 10 pieces via Kickstarter as a way to get the watch into production. It pushes accuracy.
  • Bathys promises that the Cesium 133 will be produced first as a limited edition of 20 watches in 2014, with more watches to perhaps come later. The projected price of each Bathys Cesium 133 atomic clock watch is $12,000.
  • The only stable caesium isotope is 133 Cs, with 78 neutrons. Although it has a large nuclear spin (7 2 +), nuclear magnetic resonance studies can use this isotope at a resonating frequency of 11.7 MHz. Decay of caesium-137.
Atomic

Caesium is a monoisotopic element and its atomic weight is determined solely by its isotope 133Cs. The Commission last revised the standard atomic weight of caesium in 2013 based on the latest Atomic Mass Evaluation by IUPAP.

Cesium 133SOURCEAtomic weights of the elements: Review 2000 by John R de Laeter et al. Pure Appl. Chem. 2003 (75) 683-800
© IUPAC 2003

CIAAW

Caesium
Ar(Cs) = 132.905 451 96(6) since 2013
The name derives from the Latin caesius for 'sky blue', which was the colour of the caesium linein the spectroscope. Caesium was discovered by the German chemist Robert Wilhelm Bunsen and the Germanphysicist Gustav Robert Kirchhoff in 1860. It was first isolated by the German chemist Carl Setterbergin 1882.

Cesium 133 Half-life

There are several radioactive isotopes of cesium ranging from cesium-114 to cesium-145. The radioactive isotopes have a wide range of half-lives ranging from about 0.57 seconds (cesium-114) to about 3X10+6 years (cesium-135). The radioactive isotopes cesium-137 and cesium-134 are significant fission products because of their high fission yield, their long half-lives, and their biochemical similarity to potassium. The fission yield of cesium-137 in nuclear reactions is relatively high, about 6 atoms of cesium-137 are produced per 100 fission events. Cesium-137 has a radioactive half-life of about 30 years and decays by beta decay either to stable barium-137 or a meta-stable form of barium (barium-137m). The metastable isotope (barium-137m) is rapidly converted to stable barium-137 (half-life of about 2 minutes) accompanied by gamma ray emission whose energy is 0.662 MeV. The first beta decay mode that forms barium-137m accounts for roughly 95% of the total intensity, while the second mode accounts for about 5%. Radioactive cesium-134 primarily decays to stable barium-134 by beta decay accompanied by gamma ray emissions or less frequently to stable xenon-134 by electron capture (EC) accompanied by a single gamma ray emission. The energy of the various gamma rays are in the range of 0.24-1.4 MeV.