A nucleus $X$ undergoes decay to become a nucleus $Y$ by first emitting an alpha particle and then two beta particles. Which statement concerning this nuclear decay is correct?
- ABeta particle decay occurs when a proton changes into a neutron.
- BNucleus $Y$ has the same nucleon number as nucleus $X$.
- CNucleus $Y$ is an isotope of nucleus $X$.
- DThe total mass of the products is equal to the mass of the initial nucleus $X$.