There are three types of Particulate Radiation and they are of little concern to the average radiographer.
Particulate Radiation is different from X and Gamma Rays they have mass and do not travel at the speed of light.
However, Particulate Radiation will penetrate matter, will case ionization and cannot be detected by human senses.
Alpha Radiation as discussed in Lesson 4 has a positive charge and is slow and heavy.
Alpha Particles ionize atoms by removing electrons as they pass but they do not penetrate deeply.
Beta Particles (High Speed Electrons) have a negative charge and because they are lightweight, they are not as ionizing alpha particles.
Neutron Radiation has peculiar penetrating qualities. It penetrates many heavy elements with ease and is absorbed readily by many lighter elements, particularly Hydrogen.