Answer :
Final answer:
Cesium-137 has a half-life of 30 years, meaning it takes 30 years for half of it to decay. In terms of half-lives, it will take approximately five half-lives, or 150 years, for 128-grams of Cesium-137 to Radioactive Decay to only 4-grams.
Explanation:
Cesium-137 is a radioactive isotope that decays through a process called fission, which essentially means that it loses its radioactivity over time. The rate at which this happens is measured by its half-life - the time it takes for half of the isotope to decay. In the case of Cesium-137, its half-life is approximately 30 years.
Thinking in terms of half-lives, if we start with 128 grams, after one half-life of 30 years, we will have 64 grams left. After two half-lives (60 years), we would have 32 grams left.
After three half-lives (90 years), we would have 16 grams. After four half-lives (120 years), we are left with 8 grams, and finally, after five half-lives (150 years), the original 128 grams of Cesium-137 would have decayed to 4 grams.
So, **it will take approximately 150 years** for 128-grams of Cesium-137 to decay to only 4-grams if its half-life is 30 years.
Learn more about Radioactive Decay here:
https://brainly.com/question/1770619
#SPJ11
