Two different radioactive isotopes decay to 10% of their respective original amounts. isotope a does this in 33 days, while isotope b does this in 43 days. what is the approximate difference in the half-lives of the isotopes? 3 days 10 days 13 days 33 days

3 days  

Explanation:

For each isotope, we must use the integrated rate law for a first order reaction to get the rate constant k, then use that to calculate the half-life t_½.

1. Isotope A

The integrated rate law for a first-order decay is  

ln(N₀/N) = kt

Data:

N₀ = 100 %

N =    10 %

 t =    33 da

(a) Calculate the value of k

(b) Calculate the half-life

2. Isotope B

Data:

N₀ = 100 %

N =    10 %

 t =    43 da

(a) Calculate the value of k

(b) Calculate the half-life

3. Calculate the difference in half-lives

Difference = 12.9 da - 9.9 da ≈ 3 da

The graphs below show the decay curves for isotopes A and B. The half-lives are approximately 10 da and 13 da, a difference of 3 da.

answer: h+ its less than oh

explanation:

answers: to make sure that all of the broken pieces of tablet were added to the water, to allow for fair comparison of all three trials, with different particle sizes to avoid experimental error