A sample contains 10g of radioactive isotope. How much radioactive isotope will remain in the sample after 3 half-lives?

After 1 half-life (500 years), 500 g of the parent isotope will remain. After 2 half-lives (1000 years), 250 g of the parent isotope will remain. After 3 half-lives (1500 years), 125 g of the parent isotope will remain. After 4 half-lives (2000 years), 62.5 g of the parent isotope will remain.

Explanation:

potential energy is directly proportional to height.

more height = more potential energy.

greatest increase in height = greatest increase in potential energy

where are the points with the greatest increase in height ?

has to be c-e or d-e .