Question

The​ half-life of radium is 1690 years. If 20 grams are present​ now, how much will be present in 250 ​years?

Answer 1

Answer:

  18.05 g

Step-by-step explanation:

The multiplier of the initial quantity is ...

  (1/2)^(t/1690)

so, for t=250, this becomes ...

  (1/2)^(250/1690) ≈ 0.902545

Then the quantity remaining of the initial 20 g is ...

  (20 g)(0.902545) ≈ 18.05 g