Cobalt-60 has a half-life of about 5 years. How many grams of a 300 g sample will remain after 20 years?
(Points : 1)
20 years is 4 half-lives, so there would be
300 * (1/2)^4
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To find out how many grams of a 300 g sample of Cobalt-60 will remain after 20 years, we can use the half-life formula.
The half-life (t1/2) of Cobalt-60 is given as 5 years. This means that after every 5 years, the amount of Cobalt-60 will reduce to half of its original value.
Since we want to know how much will remain after 20 years, we first need to determine how many half-lives have passed.
20 years divided by 5 years per half-life gives us 4 half-lives.
After each half-life, the amount of Cobalt-60 is reduced by half. So, after 4 half-lives, the remaining amount would be (1/2)^4 = 1/16th (or 0.0625) of the original amount.
Let's calculate the remaining grams:
300 g x 0.0625 = 18.75 g
Therefore, after 20 years, approximately 18.75 grams of Cobalt-60 will remain from a 300 g sample.