A helium atom with two neutrons and protons known as an "alpha particle" is extremely energetic and active.
The least penetrating and most ionizing particles are these ones.
Due to their great ionization strength, they can seriously harm the body if they enter it. Compared to other types of nuclear radiation, alpha particles are slow and hefty.
The alpha particles have a kinetic energy of 5 MeV.
The alpha particles have an impact on the photographic plates.