Cesium (Cs)

Atomic number:	55
Atomic weight:	132.9054
Average concentration in ocean:	2.3 nmol/kg
Residence time:	330,000 years

Distribution in ocean
Cesium has a conservative distribution in the ocean. The concentration is relatively constant vertically and horizontally (data).

Speciation
Cesium exists in seawater as the Cs⁺ ion.

Residence time
The cesium residence time is from Tracers in the Sea (Broecker, W. S. and Peng, T.-H., 1982. Eldigo Press, Palisades, NY). It was calculated from the global average river input.

Analysis
Cesium can be determined by neutron activation analysis, atomic absorption spectrometry or mass spectrometry.

References