- Oct 2017
You've got the right idea, but it's very complicated. There are models in the literature that try to predict decay or nuclear reaction properties based on nuclear physics and quantum mechanics applied to configurations of nucleons with particular states, with varying degrees of success. An example is the "coupled-channel" models.What causes them to pop? ...no one knows ... One idea (off the top of my head) is that there is a flux of unknown particles whizzing around ... different isotopes have different interaction cross sections for them , when an atom interacts with one it just pops ...Imagine bullets flying around and atoms are balloons of different sizes, a big balloon equates to a short half life
However, although a decay probability or interaction cross section can be estimated based on knowledge of the constituent particles, all experiments lead to the conclusion that there is no explicit mechanism exists that "causes" a decay (rather than not) for a given system at a particular time; even in models where there are intermediate states (e.g. excited states) and/or evolution of state as a function of time (reaction kinetics), the decays/reaction outcomes are completely random.