One kind of radioactivity is called “alpha decay.” For example, the nucleus of a radium-220 atom can spontaneously split into a radon-216 nucleus plus an alpha particle (a helium nucleus containing...

One kind of radioactivity is called “alpha decay.” For example, the nucleus of a radium-220 atom can spontaneously split into a radon-216 nucleus plus an alpha particle (a helium nucleus containing two protons and two neutrons).

Consider a radium-220 nucleus that is initially at rest. It spontaneously decays, and the alpha particle travels off in the

direction. What can you conclude about the motion of the new radon-216 nucleus? Explain your reasoning.

(A) It is also moving in the direction.

(B) It remains at rest.

(C) It is moving in the direction.