Answer :
If the half-life of cesium-137 is approximately 30 years, after 90 years, only one-eighth (1/2 * 1/2 * 1/2) of the original amount of cesium-137 will remain in the sample.
To determine the amount of cesium-137 remaining after 90 years, we can use the concept of half-life.
The half-life of cesium-137 is approximately 30 years, which means that in every 30-year period, the amount of cesium-137 is reduced by half.
After 30 years, half of the cesium-137 will remain.
After another 30 years (60 years in total), half of the remaining cesium-137 will remain.
After another 30 years (90 years in total), half of the remaining cesium-137 will remain.
Therefore, after 90 years, only one-eighth (1/2 * 1/2 * 1/2) of the original amount of cesium-137 will remain in the sample.
To calculate the exact amount remaining, we need to know the initial quantity of cesium-137 in the sample.
To know more about half-life, refer here:
https://brainly.com/question/24710827#
#SPJ11