Question

The half-life of carbon-14 is 5,730 years. How many grams of parent material will remain from a 120-gram sample of carbon-14 after 2 half-lives?

Answer 1

Answers to choose from:
90

60

30

15

Answer 2

First! you have to know the definition of Half-life

a material goes through the period of half-life will remains only half of its weight

so the 120-gram sample of Carbon go through two half-lives

the first time it will remain 60-gram
for the second time will remain only 30-gram