Which of the following remains constant during the motion of a projectile fired from a planet? A. Momentum

B. Kinetic energy

C. Horizontal component of velocity

D. Vertical component of velocity

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