Question

How many grams of cobalt-60 will remain after three half-lives?

Answer 1

1.25

Step-by-step explanation:

After 3 half lives and 17,190 years have gone by. 1.25

Answer 2

Cobalt-60 decays, with a half-life of 5.3 years, to the element nickel-60 by the emission of a 0.32 MeV beta particle.