What happens when a penny is dropped from a height of 20 meters? a. it falls at a constant velocity b. its mass doubles for every second it falls c. the force of gravity causes it to accelerate d. it changes direction every 9.8 meters

Daughter element the new element produced along with a decay particle in a nuclear transmutation 2. half-life the substance that decays in a nuclear transmutation 3. parent element the change of one chemical element into another by nuclear decay or radioactive bombardment 4. transmutation the time required for the decay of one-half of the atoms in a sample of radioactive material