Question

Suppose you have 50 grams of a radioactive isotope with a half-life of 2 years. How much of the isotope will you have after 4 years?

A. 50 g
B. 25 g
C. 12.5 g
D. 6.25 g

Answer 1

50/2 = 25
25/2 = 12.5

In 4 years there will be 12.5 g of the radioactive isotope left

Hope this helps :)

Answer 2

The answer is C 12.5 g because after 2 years, 50 g goes to 25, and after another 2 years, it goes to 12.5 g

Answer: C