Which of the following are types of ionizing radiation?

Ionizing radiation refers to radiation that carries enough energy to liberate electrons from atoms or molecules, thereby ionizing them. Among the options provided, the combination of alpha particles, beta particles, and gamma rays represents three distinct types of ionizing radiation.

Alpha particles are heavy, positively charged particles composed of two protons and two neutrons, emitted from the nucleus of radioactive atoms. They have low penetration ability and can be stopped by a sheet of paper but can cause significant biological damage when ingested or inhaled.

Beta particles are high-energy, high-speed electrons or positrons emitted from a decaying atomic nucleus. They have greater penetration power than alpha particles but can still be stopped by materials such as plastic or glass.

Gamma rays, on the other hand, are electromagnetic radiation of high frequency and energy. They have a very high penetrating ability and can pass through most materials, requiring dense substances like lead or several centimeters of concrete for shielding.

Thus, the choice comprising alpha particles, beta particles, and gamma rays accurately includes only those forms of radiation known for their ionizing properties, highlighting the potential for chemical changes and biological effects in matter they interact with. This makes it the correct answer.