Hi,
island of stability is an area surrounded by lot of really fast decaying elements. Today I will write about island of stability which is on the other hand area with hypotheticly and relatively stable elements.
By area I do not mean some place. It is rather area in periodic table of elements extended for various isotopes.
The more heavy nucleus of atom gets, the easier and better for him it is to decay, potentially killing everything around, or at least giving some nice brain tumors. But then at some point, some of the elements are smart enough to stay stable, like a boss. Those are the elements in island of stability, this island is not very big and we can just guess its highest peaks.
The elements are much more stable because of the shape of their nucleus. The problem is that the nucleus becomes a bit deformed, even elliptical.
Anyway there is this thing called “magic number” which is a number of protons or neutrons which can lead to good shape which is stable, this means round normally. Such numbers are for example 2,8,20,28… 126. There are few other hypothetical (196,236…), elements which live on this island should have some combination of these numbers which would make them much much more stable than the stuff around.
For example Ununoctium which is the last known element has half-life of only 890 microseconds.
The island should come in proton number of roughly 120 and little bit more.

Picture showing the island of stability (white circle). The most stable elements could last for longer than an year.
There is even hypothetical second island. It would have to be around element 164. Who knows how many more theoretical elements there are before we will simply not be able to stick all these protons and neutrons together (not that we are sticking them).
Dragallur