What are the two main types of radiation emitted from radioactive isotopes?

The two main types of radiation emitted from radioactive isotopes are alpha and beta radiation. Alpha radiation consists of particles made up of two protons and two neutrons, which are essentially helium nuclei. This type of radiation is relatively heavy and has low penetration power, meaning it can be stopped by a sheet of paper or even the outer layer of human skin. However, it is highly ionizing, making it very damaging if ingested or inhaled.

Beta radiation, on the other hand, consists of high-energy, high-speed electrons or positrons emitted from a decaying nucleus. Beta particles have greater penetration abilities than alpha particles but can still be stopped by materials such as plastic or a few millimeters of aluminum. Beta radiation is less ionizing than alpha radiation but can still cause significant biological damage.

In contrast, the other options presented refer to different types or forms of radiation. X-ray and gamma radiation are both forms of electromagnetic radiation, primarily arising from electron interactions or nuclear transitions rather than directly from isotopes in decay. Positron and neutron radiation involves specific subatomic particles, with positrons being a type of beta radiation but not constituting a main type alongside alpha or beta decay processes. Microwave and infrared radiation fall under non-ionizing electromagnetic