Another way of proving that there are discreet energy levels, is when gamma radiation is emitted from the daughter nucleus. When an atom undergoes alpha decay, it emits alpha particles with discreet energy levels. The atom can either either emit these alpha particles with maximum kinetic energy which leaves the daughter nucleus in a ground state, or it can emit the alpha particles with minimum kinetic energy which leaves the daughter nucleus in an excited state. When this happens gamma radiation is emitted, and this radiation is of a discreet frequency which is further evidence for the existence of nuclear energy levels.
13.2.4 - Describe Beta decay, including the existence of the neutrino
When Beta decay occurs a neutron changes into a proton and an electron is released from the atom. The atomic number increases as there is now an extra proton, however the mass number stays the same.
When Beta-plus decay occurs a proton changes into a neutron and a positron is released from the atom. The atomic number decreases as there is now one less proton, but the mass number stays the same.
When scientist were looking at this, they realised that with every experiment the energy from mass defect was not equal to the energy from the electrons and the positrons. Which meant suggested that there was energy being lost in a form that wasn't originally detected. For this reason scientists proposed there was being another particle emitted during the beta and beta-plus decay. This particle has no charge and extremely low mass, which it is so hard to detect.
For Beta decay an electron is released with an anti neutrino
For Beta-plus decay a positron is released with a neutrino
