Question

The half-life of cesium 137 is 30 years. Suppose we have a 130mg sample. What will be the mass of the sample after 60 years?

Answer 1

The mass of the sample after 60 years would be 32.5mg.

Step-by-step explanation:

The half-life of cesium 137 is 30 years. This means that it takes 30 years for half of the original sample to decay. If we start with a 130mg sample, after 30 years, half of it will decay and we will have 65mg remaining. After another 30 years (60 years total), half of the remaining 65mg will decay, leaving 32.5mg.

Answer 2

The mass of the sample after 60 years will be 32.5 mg.

Step-by-step explanation:

The half-life of cesium 137 is 30 years. This means that after every 30 years, half of the original sample will decay. So, after 60 years, two half-lives would have passed. To find the mass of the sample after 60 years, we can use the formula:

Final mass = Initial mass * (1/2)^(number of half-lives)

Given that the initial mass is 130 mg and two half-lives have passed, the equation becomes:

Final mass = 130 * (1/2)^2 = 130 * (1/4) = 32.5 mg