Thallium (Tl)

Atomic number:	81
Atomic weight:	204.383
Average concentration in ocean:	64 pmol/kg
Residence time:	yr

Distribution in ocean
Dissolved thallium has a conservative distribution in the ocean. Concentrations are uniform, within the resolution of the data, both vertically and horizontally (data).

Speciation
Thallium is present in the +I oxidation state as Tl⁺ and TlCl⁰.

Analysis
Thallium is determined by isotope dilution, mass spectrometry.

References & Notes