Effect of radioactive decay on the structure

Question

In case of electricity, the understanding is that conductivity occurs only on the surface of the element.Is it true for radio-active decay as well ?

If not and the decay occurs within the element, then it should ideally result in the element weakening structurally since its possible that the resulting atom may not bond with its surrounding atoms (nuclear transmutation).

For example over time a sample of radium may decay into radon gas. If the decay is internal then it will imply that radon gas accumulates overtime (trapped) until it finds a release point ( similar to volcanoes ).

As per my understanding of decay, the second case should be true. Is my understanding correct?

Answer 1

Yes: radioactivity is (almost) completely independent of the environment, so atoms will decay all through the bulk of the material. And yes: this does in theory harm the structural stability of the material, although it takes a whole lotta decay to change it in a measurable way (for a related effect Google nuclear reactor embrittlement).