hmm totally disagree... the radioactive decay has a cause.
It happens in nucleus which are not stable (too heavy too many neutrons for a certain number of protons etc... well causes are known).
You can't predict when a single atom will decay but you can predict very well when a whole bunch of them will decay (statistics... following Poisson) and at which rate.
Anyhow, you know it will happen because (hence causality) those atoms/nucleus are unstable...
You are confusing cause with necessary and sufficient condition. They are 2 different concepts. An unstable nucleous is a pre condition, not a cause.
Necessary and sufficient conditions are concepts from logic, but dealing with much the same thing, no? What a cause do is to provide the sufficient conditions for an event to happen.
I do agree that, as far as we know, there are events in the quantum level that happen randomly without a cause. But that might be understood a bit differently: their sufficient conditions are none, except for a probabilistic factor.
A cause is not a mere sufficient pre condition, it is a NECESSARY condition. Given a cause, the caused event must necessarily happen.
The necessary condition X of event A means, given event A, then X necessarily occurred. If cause is a necessary condition, then it is follows that all causes are necessary to its effects.
But that's not the case, since it is plausible that an effect A could be caused by a number of different causes. None of them could then be said to have occurred based of the observation of the effect. So, in my opinion, it is more sensible to relate cause with what provides sufficient conditions, not with necessary conditions.
All causes are necessary to its effects, provided the effects are caused. That is the problem, not all effects need a cause, but just need a sufficient condition. In the case of radioactive decay, it needs a sufficient condition, not necessarily a necessary condition (cause).