Question

When a proton and a neutron is combined together to form a nucleus, it emits a gamma ray of energy

Answer 1

In gamma decay, only energy, in the form of gamma rays, is emitted. Alpha and beta decay occur when a nucleus has too many protons or an unstable ratio of protons to neutrons. When the nucleus emits a particle, it gains or loses one or two protons, so the atom becomes a different element.