Tantalum

Location:  Group 5, Period 6
Atomic Weight:  180.9479
Coordination Number:  6, 7, 8
Chemical Form in Solution:  TaOF₆^-3
(coordination numbers in green are observed less frequently)

Storage & Handling:  Keep tightly sealed when not in use. Store and use at 20 ± 4°C. Do not pipet from container. Do not return portions removed for pipetting to container.

Chemical Compatibility:  Soluble in concentrated HCl and dilute HF / HNO₃. Avoid neutral to basic media. Unstable at ppm levels with metals that would pull F^- away (i.e. - do not mix with Alkaline or Rare Earths or high levels of transition elements unless they are fluorinated). Stable with most inorganic anions, provided it is in the chemical form shown above.

Stability:  2-100 ppb levels stable (alone or mixed with all other metals that are at comparable levels) as the TaOF₆^-3, for 2 months at the 2-10 ppb level in 1% HNO₃ / LDPE container and for 5 months at the 100 ppb level under same conditions. 1-10,000 ppm single element solutions as the TaOF₆^-3 are chemically stable for years in 2-5% HNO₃ / trace HF in an LDPE container.

Ta Containing Samples (Preparation & Solution):  Metal (soluble in HF / HNO₃); Oxide - very resistant to all acids including HF (fusion with K₂S₂O₇, KOH, or Na₂CO₃); Organic Matrices (dry ash at 450°C in Pt⁰ and dissolve by fusing with Na₂CO₃ or K₂S₂O₇).