When something non-radioactive has been exposed to radiation, and itself becomes radioactive, what happens to it?

Question

Does it mean that some of the atoms have absorbed neutrons and are now an unstable isotope thus emitting their own neutrons? How are irradiated things dangerous?

In: Physics

Answer 1

There is a difference between radioactive material and radioactivity. Radioactive material contains elements that are unstable and decay into stable forms by releasing energy and particles. That release of particles and energy y (called radioactivity) has various forms.

Radioactivity making some other non-radioactive element radioactive is very rare. This is becuase specific or sufficient energies are needed to transform elements into radioactive ones.

Bananas contain a naturally ocurring radioactive element. If you remove the radioactive element from bananas, Potassium-40, and put it into an apple, the apple would now be considered radioactive material because it contains potassium- 40. Nothing else in the apple would be radioactive, even when exposed to the radioactivy from the potassium-40. If you put enough potassium-40 into the apple, damage would start to occur to the molecules of the apple caused by the radioactivity of the potassium 40, but the non radioactive elements in the apple would not become radioactive.

In the circumstance when the energy of radioactivity is specific or sufficient enough to alter specific elements in a material, then a non radioactive material can become radioactive. Note that this is a reaction and it is not the result ofthe radioactivity “contaminating” the material. Radioactivity cannot contaminate anything. However something can be contaminated by radioactive material.

The creation of radioactive material by radiation always involves a reaction. For example, if you bombard a slab of bismuth metal with alpha radiation (a type of radioactivity, not radioactive material) some Bismuth atoms will absorb the ralpha particles, release 2 neutrons, and turn into astatine-211. Astatine-211 is radioactive.

The bismuth slab, which is still mostly bismuth, is radioactive material only because it contains atoms of astatine-211 which is radioactive because it releases radioactivity.