Half-Life Calculations
Chemistry ⇒ Nuclear Chemistry
Half-Life Calculations starts at 11 and continues till grade 12.
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Define half-life in the context of nuclear decay.
Describe the mathematical relationship between the number of half-lives and the fraction of radioactive material remaining.
Explain how the concept of half-life is used in radiometric dating.
Explain why the half-life is useful in determining the safety of radioactive waste disposal.
Explain why the half-life of a radioactive isotope is considered a constant property.
A 200 g sample of a radioactive isotope decays to 25 g in 3 hours. What is the half-life of the isotope?
A 50 g sample of a radioactive isotope decays to 6.25 g in 3 hours. What is the half-life?
A radioactive isotope decays from 64 g to 8 g in 12 hours. What is its half-life?
A radioactive isotope has a decay constant of 0.231 day-1. Calculate its half-life.
If 25% of a radioactive sample remains after a certain period, how many half-lives have passed? (1) 1 (2) 2 (3) 3 (4) 4
Which equation is used to calculate the remaining quantity of a radioactive substance after a certain time? (1) N = N0e-λt (2) N = N0 + λt (3) N = N0t/λ (4) N = N0eλt
Which of the following best describes the decay of a radioactive substance? (1) Linear (2) Exponential (3) Logarithmic (4) Quadratic
Which of the following best describes the relationship between half-life and decay constant? (1) They are directly proportional. (2) They are inversely proportional. (3) They are unrelated. (4) They are equal.
The decay constant (λ) is related to half-life (t1/2) by the equation t1/2 = _______.
The half-life of carbon-14 is approximately _______ years.
The time taken for a radioactive sample to reduce to one-eighth of its original amount is _______ times its half-life.
True or False: After two half-lives, 75% of a radioactive sample has decayed.
True or False: The half-life of a radioactive isotope can be changed by chemical reactions.
True or False: The half-life of a radioactive isotope can be used to estimate the age of ancient artifacts.
True or False: The half-life of a radioactive isotope depends on the amount of substance present.
