An element Y has a half life of 14.3years. Determine the mass of Y that will be remaining of 57.2years if the original mass of Y is 400g
We can use the radioactive decay formula to solve the problem:
N = N0 (1/2)^(t/h)
where:
N = final mass
N0 = initial mass
t = time elapsed
h = half life
We know that the half life of Y is 14.3 years, so we can use this value for h. We also know that the time elapsed is 57.2 years.
Using the formula:
N = N0 (1/2)^(t/h)
N = 400g (1/2)^(57.2/14.3)
N = 400g (1/2)^4
N = 400g (1/16)
N = 25g
Therefore, the remaining mass of Y after 57.2 years is 25g.