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AryaUnderfoot
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Homework Statement
Archeologists removed some charcoal from a Native American
campfire, burned it in O2, and bubbled the CO2 formed into
Ca(OH)2 solution (limewater). The CaCO3 that precipitated was
filtered and dried. If 4.58 g of the CaCO3 had a radioactivity of
3.2 d/min, how long ago was the campfire?
Homework Equations
C + O2 --> CO2
CO2 + Ca(OH)2 --> CaCO3 + H2O
The Attempt at a Solution
Activity = kN
So k = Activity/N = (3.2 atoms/min)/(0.04576 mol * 6.022*10^23 atoms/mol)
= 1.2*10^-22 min^-1
half life = ln2/k
= 5.776*10^21 min
And that's all I know..I don't have the initial and final moles of the CaCO3, so how should I calculate the time that passed?