What type of radiation is described as being large in size, with a short range, and stopped by thin paper?

The type of radiation that is described as being large in size, having a short range, and being stopped by thin paper is alpha radiation. Alpha particles consist of two protons and two neutrons, making them relatively large compared to other types of radiation. Due to their sizable mass and positive charge, they have limited penetrating power and can only travel a few centimeters in the air.

When it comes to interaction with materials, alpha particles can be easily stopped by even very thin barriers, such as a sheet of paper or the outer layer of human skin. This characteristic makes alpha radiation relatively safe in terms of external exposure; however, if alpha-emitting materials are ingested or inhaled, they can pose significant health risks.

The other types of radiation do not fit the described characteristics. Beta radiation is smaller and can penetrate beyond paper, gamma radiation is highly penetrating and requires dense materials to be effectively blocked, and neutrons have different behaviors in terms of range and penetration, often requiring heavy materials like lead or concrete to shield against them effectively.