Question

When a nucleus at rest emits a beta particle, it is found that the velocities of the recoiling nucleus and the beta particle are not along the same straight line. How can this be possible in in view of the principle of conservation of momentum?

Answer 1

The motion of subatomic particles are better explained with quantum physics. Even if we try to explain the given situation with Newtonian physics, it suggests that in view of the principle of conservation of momentum there must be additional subatomic particle released during the beta emission. As we know there is antineutrino also released during the beta emission.