Question

A radioactive cloud may contain Iodine-131, which has a half-life of 8 days. If the waste must decay to a concentration of less than 0.1% to be considered safe, it will take approximately ___ days to reach safe levels.

Answer 1

The correct answer for the question that is being presented above is this one: " 4 days." A radioactive cloud may contain Iodine-131, which has a half-life of 8 days. If the waste must decay to a concentration of less than 0.1% to be considered safe, it will take approximately 4 days to reach safe levels.

Answer 2

Answer:

100/2 ➙ 50/2 ➙  25/2 ➙  12.5/2 ➙ 6.25/2 ➙  3.13/2 ➙  1.56/2 ➙  0.78/2 ➙  0.39/2 ➙  0.195/2 ➙  0.0975

10 half lives x 8 days/half live = 80 days

Explanation: