Answer:
19 years
Explanation:
Tritium follows a first-order decay which can be represented by the following expression.
[tex]ln(\frac{[H]_{t}}{[H]_{0}} )=-k.t[/tex]
where,
[H]t is the concentration of tritium at a certain time t
[H]₀ is the initial concentration of tritium
k is the rate constant
If we know the half-life (t1/2), we can calculate the rate constant.
[tex]k=\frac{ln2}{t_{1/2}} =\frac{ln2}{12.3y} =0.0564y^{-1}[/tex]
[tex]ln(\frac{[H]_{t}}{[H]_{0}} )=-k.t\\ln(\frac{0.34[H]_{0}}{[H]_{0}} )=-(0.0564y^{-1}).t\\t=19y[/tex]
