vocabulary: daughter atom, decay, geiger counter, half-life, isotope, neutron, radiation, radioactive, radiometric dating prior knowledge questions (do these before using the gizmo.) have you ever made microwave popcorn? if so, what do you hear while the popcorn is in the microwave? i hear pops while the popcorn is in the microwave if you turn the microwave on for two minutes, is the rate of popping always the same, or does it change? explain. it changes from time to time gizmo warm-up like an unpopped kernel in the microwave, a radioactive atom can change at any time. radioactive atoms change by emitting radiation in the form of tiny particles and/or energy. this process, called decay, causes the radioactive atom to change into a stable daughter atom.