Question

Cesium-137 has a decay constant of 0.0231 (a 30-year half-life). If you start with 15 pounds of cesium-137, how much will still be there 30 years later? Round to the nearest tenth.

Answer 1

Answer:

N = 7.5 pounds

Step-by-step explanation:

Formula for the radioactive decay is given by,

$N=N_0e^{-\lambda t}$

Here, N = Final amount

N₀ = Initial amount

λ = Decay constant

t = Duration of decay

Now we can substitute the values from the given question,

N = $15e^{-(0.0231\times 30)}$

N = $15e^{-0.693}$

N = 15(0.5)

N = 7.5 pounds