Question

A 60.0-g sample of fermium-253 was placed in a sealed vessel 9.0 days ago. Only 7.5 g of this isotope is now left. What is th

Answer 1

Answer:

A

Explanation:

3 days later: 60/2=30

6 days later: 30/2=15

9 days later: 15/2=7.5