If a radioactive element has a half-life of 5760 years,and the amount of parent material remaining is one-fourth of the original amount,the specimen is about
A)11,520 years old.
B)17,280 years old.
C)23,040 years old.
D)28,800 years old.

Question

Quizplus · Accepted Answer

The specimen is about 11,520 years old because it takes two half-lives (5760 years each) for the amount of parent material to reduce to one-fourth of the original amount.

If a Radioactive Element Has a Half-Life of 5760 Years,and