Half-Life and Radioactive Decay Kinetics

Chemistry ⇒ Chemical Kinetics and Equilibrium

Half-Life and Radioactive Decay Kinetics starts at 11 and continues till grade 12. QuestionsToday has an evolving set of questions to continuously challenge students so that their knowledge grows in Half-Life and Radioactive Decay Kinetics. How you perform is determined by your score and the time you take. When you play a quiz, your answers are evaluated in concept instead of actual words and definitions used.

See sample questions for grade 11

Describe how the concept of half-life is used in radiometric dating.

Describe the difference between first-order and zero-order decay kinetics.

Describe the significance of the exponential decay law in radioactive decay kinetics.

Explain why radioactive decay is considered a first-order process.

A 200 mg sample of a radioactive isotope decays to 25 mg in 3 hours. What is the half-life of the isotope?

A 50 g sample of a radioactive isotope has a half-life of 2 hours. How much will remain after 6 hours?

A radioactive element has a half-life of 12 years. How long will it take for 90% of the sample to decay?

A radioactive isotope decays to 1/32 of its original amount in 25 days. What is its half-life?

If a radioactive isotope has a half-life of 20 minutes, what percentage of the original sample remains after 1 hour? (1) 12.5%, (2) 25%, (3) 50%, (4) 6.25%

If a radioactive sample has a half-life of 5 hours, what fraction of the original sample remains after 15 hours? (1) 1/2, (2) 1/4, (3) 1/8, (4) 1/16

Which equation represents the number of undecayed nuclei (N) at time t for a first-order decay process? (1) N = N₀e^-kt, (2) N = N₀ - kt, (3) N = N₀e^kt, (4) N = N₀/2^t

Which of the following best describes radioactive decay? (1) A chemical reaction, (2) A nuclear reaction, (3) A physical change, (4) A phase transition

Fill in the blank: After n half-lives, the fraction of the original sample remaining is _________.

Fill in the blank: The activity (A) of a radioactive sample is given by A = _________.

Fill in the blank: The decay constant (k) has units of _________.

Fill in the blank: The mathematical relationship between the half-life (t_1/2) and the decay constant (k) for a first-order reaction is t_1/2 = _________.

True or False: After two half-lives, 25% of the original radioactive sample remains.

True or False: The activity of a radioactive sample is directly proportional to the number of undecayed nuclei.

True or False: The decay constant and half-life are inversely related.

True or False: The half-life of a radioactive isotope can be used to estimate the age of ancient objects.