Answer:
Of alpha, beta and gamma radiation, gamma radiation has the greater ability to penetrate either shielding or living tissue. The penetration issue aside, a contact source that is an alpha emitter can do more tissue damage than beta or gamma radiation. Alpha and beta radiation are particulate radiation. They involve a particle. Gamma radiation is electromagnetic radiation of high energy. Use the links below to learn more about each type of radiation and get a handle on what's up.