All Problems

Radioactivity

Problem 6.220

Find the decay constant and the mean lifetime of \(\mathrm{Co}^{55}\) radionuclide if its activity is known to decrease \(4.0 \%\) per hour. The decay product is nonradioactive.

Reveal Answer
λ=(1/t)ln(1η)η/t=1.1105 s1,τ=1/λ=1years\lambda=-(1 / t) \ln (1-\eta) \approx \eta / t=1.1 \cdot 10^{-5} \mathrm{~s}^{-1}, \tau=1 / \lambda= 1 \text {years}