Build a nucleus by adding protons and neutrons, and watch its isotope notation update live. Nuclei with too many or too few neutrons for their size are unstable — the Explorer predicts how they'll decay.

Watch each type of radioactive decay, compare particle properties, and practice balancing nuclear equations — then follow a real decay chain from uranium all the way toward a stable nucleus.

Run a large sample of radioactive nuclei and watch it decay tick by tick. Each nucleus decays randomly, but with enough of them the population still follows a smooth, predictable curve.

Weigh a nucleus against its own separate protons and neutrons — the nucleus is always a little lighter. That missing mass became the energy holding it together.

Split a heavy nucleus, run a chain-reaction reactor, and fuse light nuclei together like a star does — then see why both processes release energy.

Alpha, beta, and gamma radiation behave very differently. Test how well different shields stop each one, how distance protects you, and how real-world doses compare.