This activity corresponds to the topic of Nuclear Physics and Particles, in which you will understand the radioactive decay process through visual simulation and apply the exponential law.
Select an isotope, adjust the parameters, start the simulation, and solve the exercises using a calculator.
Radioactive decay is a random process by which an unstable atomic nucleus loses energy by emitting radiation. This phenomenon follows an exponential law characterized by the half-life (t½), which is the time required for half of the nuclei in a sample to decay.
N(t) = N₀ · e^(-λt) = N₀ · (1/2)^(t/t½)
Where: N₀ = initial nuclei, λ = decay constant, t½ = half-life
The blue line shows the theoretical decay N(t) = N₀·(1/2)^(t/t½). The green dots represent the actual simulation (stochastic process).
Use this tool to solve radioactive decay problems. Enter the known values and calculate the unknown.
Test your knowledge about radioactive decay. Use the simulation and the calculator to help you.
1. A sample has 1000 radioactive nuclei with a half-life of 10 years. Approximately how many nuclei will remain after 30 years?
2. Carbon-14 has a half-life of 5730 years. If a fossil contains only 25% of the original C-14, what is its approximate age?
3. What is the relationship between the decay constant (λ) and the half-life (t½)?
4. In nuclear medicine, Technetium-99m (t½ = 6 hours) is used for diagnostics. If a patient is injected with 800 MBq, what will the activity be after 18 hours?
5. After 5 half-lives, what fraction of the original sample remains undecayed?