The radioisotope radon-222 has half-life of 3.8 days. how much of a 73.9-g sample of radon-222 would be left after approximately 23 days?

First, we calculate the decay constant λ
λ = (ln(2))/T₀.₅
λ = 0.693/3.8
λ = 0.182
Then, we use the decay equation:
N(t) = N₀e^(-λt)
N(t) = 73.9 x e^(-0.182 * 23)
N(t) = 1.12g
1.12g of Radon-222 will be left after 23 days