Question

Strontium-90 has a half life of 29 years, how much strontium-90 is left from the Chicago pile reactor that was active around 87 years ago.

Answer 1

Answer:

The answer is below

Explanation:

The half life of a substance is the time required by that substance to reduce to half of its initial value. The half life is calculated using the formula:

$N(t)=N_o(\frac{1}{2} )^\frac{t}{t_\frac{1}{2} } \\\\where\ N(t)=quantity\ of\ substance \ remaining, N_o=initial\ quantity\\of\ substance, t=time\ and \ t_\frac{1}{2}=half\ life\ of\ substance$

Given that t = 87 years, half life = 29 years, therefore the quantity of strontium-90 left is:

$N(t)=N_o(\frac{1}{2} )^\frac{87}{29} \\\\N(t)=N_o(\frac{1}{2} )^\frac{t}{t_\frac{1}{2} } \\\\N(t)=N_o(\frac{1}{2} )^3\\\\N(t)=\frac{1}{8} N_o$

That is one-eight of Strontium 90 would be left after 87 years