Radioactivity
Physics ⇒ Modern Physics
Radioactivity starts at 10 and continues till grade 12.
QuestionsToday has an evolving set of questions to continuously challenge students so that their knowledge grows in Radioactivity.
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 12
A radioactive isotope has a half-life of 10 days. How many days will it take for the activity to fall to one-eighth of its original value?
A radioactive sample has a half-life of 5 years. If you start with 80 grams, how much will remain after 15 years?
A radioactive sample has an initial activity of 4000 Bq. After 3 half-lives, what is its activity?
A sample contains 1.2 x 1024 atoms of a radioactive isotope with a half-life of 2 hours. How many atoms will remain undecayed after 6 hours?
Describe one practical application of radioisotopes in medicine.
Describe the difference between alpha, beta, and gamma radiation in terms of their composition and penetrating power.
Explain why gamma emission does not change the atomic number or mass number of a nucleus.
Explain why radioactive decay is considered a random process.
If a radioactive isotope has a decay constant (λ) of 0.693 yr-1, what is its half-life?
Which law describes the rate at which radioactive nuclei decay?
Which scientist is credited with the discovery of radioactivity?
Write the nuclear equation for the alpha decay of uranium-238.
A radioactive nuclide X decays to a stable nuclide Y through two consecutive beta-minus (β-) decays. If the original nuclide X has atomic number Z and mass number A, what are the atomic number and mass number of the final nuclide Y?
A radioactive sample contains two isotopes, A and B, with half-lives of 2 hours and 6 hours respectively. If initially both isotopes have the same number of atoms, after 6 hours, what is the ratio of the number of atoms of A to B remaining?
A sample of a radioactive isotope has a decay constant of 0.115 day-1. Calculate the time required for 90% of the original nuclei to decay. (Give your answer in days, rounded to two decimal places.)
A scientist observes that a radioactive sample’s activity drops from 800 Bq to 100 Bq in 24 hours. Assuming first-order decay, calculate the half-life of the isotope.
Explain why the mass of a nucleus is always less than the sum of the masses of its individual nucleons.
State the law of radioactive decay and explain its significance in determining the age of archaeological samples.
