Question

If 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 person’s body.
None, because the radiation will bounce off the person’s body.
The radiation will be totally absorbed by the person’s body.

Answer 1

A) None, because the wall will block the radiation

Answer 2

I think the correct answer would be none, because the wall will block the radiation. Alpha particles can only penetrate a very thin sheet of paper and is totally blocked by the concrete. As these particles move through the air, it loses energy from the collisions with air molecules making it less penetrating.<span />