Question

The half life of a certain radioactive element is 1,250 years what percent of the atoms remain after 7500 years

Answer 1

Each half-life results in ~50% (1/2) of the original element remaining.

7500/1250 = 6 half-lives, so 100(1/2)^6
= 100(0.015625)
= 1.5625% of the original element would remain

Answer 2

Answer:

The amount of element after 7500 years will be 1.607% of initial amount.

Explanation:

The half life of certain elements shows the time after which half of the amount   of the element will disintegrate.

Half life of given atom = 1250 years.

The amount of element after 7500 years:

Total number of half life during this period = 7500/1250 = 6.

The amount of element after 1 half life = 50%

                            After 2nd half life = 25%

                            After 3rd half life = 12.5%

                             After 4 half life = 6.25%

                             After 5 half life = 3.125

                             After 6 half life = 1.607%

So the amount of element after 7500 years will be 1.607% of initial amount.