Question

The half-life of plutonium-238 is 87.7 years.

What percentage of the atoms in a sample of plutonium-238 will remain radioactive after 263.1 years?
%



What percentage of the atoms in the same sample of plutonium-238 will have changed to another isotope after 263.1 years?
%

Answer 1

263.1 is exactly three half-life, so the remaining portion is (1/2 x 1/2 x 1/2) of the original sample. That's 1/8 which is 12.5%

Answer 2

12.5 87.5

Step-by-step explanation: