Answer:
The correct answer is: 600,000 years
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
