Question

Question #8dcdb

Answer 1

The material left will be `1/8` of the parent material

Explanation:

Let `N g =`initial quantity of radioactive isotope

After 1 half life (1.3 billion years), `N/2 g` will remain

After 2 half lives (2.6 billion years), `N/4 g` will remain

After 3 half lives (3.9 billion years), `N/8 g` will remain