Cobalt-60 is radioactive and has a half life of 5.26 years. What percentage of a sample would be left after 20.3 years?Round your answer to 2 significant digits.
Question
Cobalt-60 is radioactive and has a half life of 5.26 years. What percentage of a sample would be left after 20.3 years?Round your answer to 2 significant digits.
Solution
To solve this problem, we need to use the formula for exponential decay which is:
N = N0 * (1/2)^(t/T)
where: N is the final amount of the substance, N0 is the initial amount of the substance, t is the time that has passed, and T is the half-life of the substance.
In this case, we want to find N/N0, the fraction of Cobalt-60 left after 20.3 years. We know that T = 5.26 years.
So, we substitute these values into the formula:
N/N0 = (1/2)^(20.3/5.26)
Calculating the exponent first:
20.3/5.26 ≈ 3.86
Then, calculate the power:
(1/2)^3.86 ≈ 0.071
So, N/N0 ≈ 0.071
To express this as a percentage, we multiply by 100:
0.071 * 100 = 7.1%
So, approximately 7.1% of the Cobalt-60 would be left after 20.3 years.
Similar Questions
Iodine-125 is radioactive and has a half life of 60.25 days. What percentage of a sample would be left after 21.3 days?Round your answer to 2 significant digits.
Radium-226 is radioactive and has a half life of 1600. years. What percentage of a sample would be left after ×7.57103 years?Round your answer to 2 significant digits.
Strontium-90 is radioactive and has a half life of 28.8 years. What percentage of a sample would be left after 108. years?Round your answer to 2 significant digits.
Tin-129 is radioactive and has a half life of 2.23 minutes. What percentage of a sample would be left after 10.6 minutes?Round your answer to 2 significant digits.
Hydrogen-3 is radioactive and has a half life of 12.3 years. What percentage of a sample would be left after 3.81 years?Round your answer to 2 significant digits.
Upgrade your grade with Knowee
Get personalized homework help. Review tough concepts in more detail, or go deeper into your topic by exploring other relevant questions.