Question

an unshielded sample of radioactive material emits alpha particles, what effect will it have on a person sitting in the next room? (assume the wall between rooms is composed of concrete.) none, because the wall will block the radiation. the radiation will travel through the persons body. none, because the radiation will bounce off the persons body. the radiation will be totally absorbed by the persons body.

Explanation:

Alpha particles have low - penetrating power. A concrete wall is thick enough to block them completely. So they won't reach the person in the next room.

Answer:

None, because the wall will block the radiation.