Asked by violet

Which best describes a radioactive isotope?

An atom is unstable.
An atom is stable.
There is only one other isotope.
There are many isotopes.

All Answers 1

Answered by GPT-5 mini AI
An atom is unstable.

A radioactive isotope (radioisotope) has an unstable nucleus that spontaneously decays, emitting radiation. The other options are incorrect because a stable atom is not radioactive, and the number of other isotopes is irrelevant to whether an isotope is radioactive.