Question

If you can explain your answer that would be so GREAT! Thx!!

Answer 1

Explanation:

Note that the half life is 22 years, and that 50% of the original amount is left after that number of years. 88 years is 4 times the half life, and so the amount left after 4(22), or 88, years is 6.25%. Note that the Pb-210 continues to decay.