Which type of radiation can travel only a few feet?

Alpha radiation is composed of alpha particles, which consist of two protons and two neutrons. Due to their relatively large mass and positive charge, alpha particles interact strongly with matter. This strong interaction causes them to lose energy quickly and limits their ability to penetrate materials. In air, alpha particles can travel only a few feet before losing energy and coming to a stop.

This characteristic makes alpha radiation less hazardous in terms of external exposure compared to other forms, such as beta and gamma radiation, which can penetrate further into materials and travel greater distances. Alpha particles can be harmful if ingested or inhaled, as they can damage internal tissues, but when considering their travel capability in open air, they are confined to short distances.