_{An isotope of Tc having a half-life of 6.0 h is used in bone scans.If a certain amount of this Tc is injected into the body,how long does it take for its initial decay rate to decrease BY 99%?}

Question

Quizplus · Accepted Answer

To decrease by 99%, the decay rate must reach 1% of its initial value. This requires approximately 6.64 half-lives (since (1/2)^6.64 ≈ 0.01). Therefore, 6.64 half-lives x 6.0 h/half-life = 39.84 h, which is approximately 40 h.

An Isotope of Tc Having a Half-Life of 6

_{An Isotope of Tc Having a Half-Life of 6}