C-14 has a half life if approximately 5700 years how many years will it take for the radioactivity of a sample to reach one-fourth of its original amount
A. 1425
B.5700
C.11400
D. 22800
This is an easy half-life problem. Every half-life, a substance loses half its radioactivity. So, after 2 half-lives, a substance will have a quarter of its radioactivity. 2 * 5,700 = 11,400 years answer is C
