The half-life of an isotope of an element is 5 days. The mass of a 10 gram sample of this isotope remaining after 20 days is:
a) 0.312 grams
b) 0.625 grams
c) 1.25 grams
d) 2.50 grams
Ans:
The mass of a 10 gram sample of given isotope remaining after 20 days is 0.625 grams.