The half-life of a given isotope is the amount of time it takes for half of the atoms in a sample to decay. This simulation allows you to address, using three different isotopes, notions like radioactive decay, carbon dating, half life constant. Click on one of the three isotopes to select a half-life constant. Click on [Play] to start the decay. Start a chain reaction, or introduce non-radioactive isotopes to prevent one. Control energy production in a nuclear reactor! (Previously part of the Nuclear Physics simulation - now there are separate Alpha Decay and Nuclear Fission sims.) Sample Learning Goals Describe how a neutron can give energy to a nucleus and cause it to fission.