I am completing an assignment that is covering alpha, beta, and gamma decay. I am going to try and keep this as general as possible, as I want to figure this out myself but I just looking for feedback to make sure I am on the right track. I noticed that after alpha decay, the mass of the alpha particle and daughter atom is not quite equal to the parent atom. It wants to know whether I think mass and energy are conserved relative to E=mc^2. I noticed there was roughly 8.0x10^-13 J's less after the reaction. But I did a bit of research on the speed of an alpha particle, converted the mass of the alpha particle to kg, and when I plugged them into the kinetic energy formula (ek=.5mv^2), it gave roughly the difference between the parent vs. daughter alpha particle. That being said, could some of the mass have been converted into kinetic energy of the alpha particle?