6- Among the following radiations, which ones have a continuous energy spectrum? A. gamma emission B. beta emission C. alpha emission D. X-ray E. antineutrino

B. Beta emission and D. X-ray have a continuous energy spectrum.

Beta emission has a continuous energy spectrum because the energy of the emitted beta particle can vary. This is due to the fact that the energy can be shared between the beta particle and the neutrino that is also produced during the decay.

X-rays also have a continuous energy spectrum. This is because they are produced by a process called Bremsstrahlung, or "braking radiation", in which a high-energy electron is deflected by the nucleus of an atom, causing the electron to slow down and change direction. The energy lost in this process is emitted as an X-ray photon, and the amount of energy lost can vary, leading to a continuous spectrum.