Name __________________________
Date _______________
Period _____________
Chernobyl Half-life & Radioactive Decay Problems
Cesium-137 was a radioactive isotope released at the Chernobyl nuclear reactor in April 1986 when it
exploded. The half-life of Cesium-137 is (approximately) 30 years.
Fill in the table below, and then answer the questions.
Half-lives % Cesium-137
0
% stable daughter product
“age” of sample
1
2
3
4
5
1. After 30 years what percentage of Cesium-137 is left?
2. After 60 years what percentage of Cesium-137 is left?
3. After 30 years what is the percentage of the stable daughter product?
4. The sample substance you tested consists of 87.5% stable daughter product and 12.5% Cesium-137.
a. How many half-lives have passed?
b. How old is the sample?
5. How many half-lives will the Cesium-137 have gone through after 510 years?