Question

Atoms of A decay to atoms of B with a half-life of 200,000 years. If there are 20,000 atoms of A to begin with, how long will it take for there to be 2,500 atoms of A?

Answer 1

The correct answer is: 600,000 years

Step-by-step explanation:

Half-life is the time which is essential or required to decrease a specific substance to half of its initial amount of the substance. So, if a substance has a half-life of 200,000 years then it means it takes 200,000 years to decrease or change into a new substance and remain half of its initial quantity.

half-life amount

0 20000

1 10000

2 5000

3 2500

total half-life = 3 to 2500 atoms of A

so, the time will be = 3 * 200,000 years

= 6000000