Goes radioactive? Crossword Clue

 The answer to the crossword clue "Goes radioactive" can be a noun or a verb. As a noun, the answer is FISSION. It is the process of splitting an atom into two smaller atoms, releasing energy in the process. This can cause the atoms to become radioactive.

As a verb, the answer is TO FISSION. It means to split an atom into two smaller atoms. This can be done artificially, or it can happen naturally, such as in the case of a nuclear explosion.

Here are some other possible answers for the crossword clue "Goes radioactive":

EXPOSURE

TRANSMUTATION

DECAY

ACTIVATION

IRRADIATION

The specific answer that is correct will depend on the context of the crossword puzzle.

I hope this helps!