Ok, maybe I'm out of date here. I thought radioactive decay was a result of the structure of the relevant isotope?
Of course I learned this back when there were all these little planetary systems called hydrogen, helium etc..
In addition, chemistry was almost as opaque to me as calc.
The rate of decay for any given isotope is certainly a product of structure, but the decay of an individual atom is not caused by any prior event. This has been one of the most heavily investigated phenomena in science. There are other quantum phenomena that appear to be inherently random, not just "looks like" random.
Of quantum theory could be wrong. Room for a Nobel Prize here.