Describe the characteristics of alpha particles, beta particles, and gamma rays in terms of their composition, charge, and penetrating power.

Alpha particles (α) are composed of two protons and two neutrons (a helium nucleus), have a +2 charge, and low penetrating power. Beta particles (β) are high-energy electrons, have a -1 charge, and moderate penetrating power. Gamma rays (γ) are electromagnetic radiation (photons), have no charge, and very high penetrating power.