Yes, both are the natural decay products of 238U. Usually, however, 226Ra in
natural samples is very very very low due to its reasonably short half-life
(1600 years, not the shortest in in the decay chain, but shorter than that
for 238U, 234U and 230Th). The end-product of the 238U decay chain is 206Pb,
which is not radioactive.
Yes, it can be calculated how much 226Ra you would expect if your system has
been closed for a certain amount of time (usually 5-8 times the half-life of
the shortest-lived isotope, in this case 226Ra), or if you have an
independent assessment of the age of the sample you are analyzing... but in
any case, it should be VERY low... if you have 1 mg of 238U that's about
4E-3 mmol of 238U, in which case, in an UNDISTURBED system you would have
~1.4E-9 mmol of 226Ra.. i.e. extremely low quantities...
Hope this helps
De: PLASMACHEM-L: Analytical Chem.(ICP's, DCP's, MIP's).
[mailto:[log in to unmask]] En nombre de Labolink-1
Enviado el: miércoles, 1 de marzo de 2017 11:57 p. m.
Para: [log in to unmask]
Is there a direct linear relationship between the Pb and U238 isotopes
Specifically Pb206 and Ra226
Can it be calculated?
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