Question

(25 points) A certain isotope of technetium has a half-life of 8 hours. How much of a 40 gram sample will be left after 16 hours?

A. 10 grams
B. 40 grams
C. 5 grams
D. 20 grams

Answer 1

A) 10 grams

Step-by-step explanation:

16 hours = 2 half lives

This means that the number is divided in half twice.

40/2 = 20

20/2 = 10

I hope this helps!! :)