Alpha-Particle and Beta-Particle Interactions with Matter
Alpha-particles-
interact either by passing close to the nucleus causing ionization or far away causing excitation. Each interaction causes energy lost to the particle and it will eventually stop inside the absorber.
Beta-particles-
interacts the same way alpha-particles with differences. Greater amounts of energy is lost during interactions causing elastic collisions with other particles, therefore unlike alpha-particles the path is not linear.