A particular fast-moving particle travels several feet in open air and is easily stopped by a solid material. Acute exposure is rare, but chronic effects occur from long-term exposure. Which of type of particle is most likely being described?

A beta particle can travel several feet through air but is stopped by relatively thin solid materials, such as plastic or aluminum. Alpha particles are stopped much sooner, while gamma rays and neutrons are more penetrating. The description therefore points to a beta particle, choice C.

AI-written and checked against the verified answer.