Att = 0we begin to observe two identical radioactive nuclei that have a half-life of. At t = 1min, one of the nuclei decays. Does that event increase or decrease the chance that the second nucleus will decay in the next, or is there no effect on the second nucleus? (Are the events cause and effect, or random?)

1. At t = 0 two identical nuclei have half-life,$T_{1/2}=5\min$
2. At t = 1 min one of them decays.

In the given case, the two identical nuclei with the same half-life undergo the same decay change which means it has the same disintegration rate. It implies their initial and any instant decay conditions with their nuclei number are also the same.

In the given problem and the concept, we can clearly say that the decay process of two identical nuclei will remain same. But the given case that is effect of suppose the first nuclei A has no information about when the decay process of the second nuclei say B has started.

Consider a situation that A has already started decaying and now, we are observing the decay at the last min. In this situation, there is no information about the decay state of B. Thus, these events are random.

Hence, there is no effect on the second nuclei due to the decay process.