Answer:
2 years to decay to a mass of 50g.
Explanation:
given:
100g of substance with a half life of 2 years
to a mass of 50g
Half life is the amount of time taken by a radioactive material to decay to half of its original value.
ln 2 0.693
Half life T1/2 = ---------- = -----------
λ λ
where λ = rate constant
The initial amount of 100 grams is decaying to a mass of 50 grams is half of its initial value.
Therefore, it will take 2 years for the decay.