Is there an upper limit of how heavy an element can be, and can heavier elements form in black holes?

Black holes exist only in somebody's imagination. The basis of the theory is an assumption that a body can collapse under its own gravitation. One exercise in PHYSICS 101 is to integrate the gravitation inside a sphere. If it is hollow there is no net gravitation anywhere inside. If it is solid then gravitation gets lower as you approach the center, and at the center it is zero. In real life gravitation depends a lot on the density of rocks and materials nearby, and also on centrifugal force as the body rotates. So the foundational assumption of the black hole is nonsense.

Knowledge of how a star works is equally shaky, especially since we can see that our own star does not work the way scientists think it does. Of course scientists refuse to admit that. They insist they know everything about the sun except for a few fudge factors. Well, anybody can see that the surface of the sun is cooler than the photosphere above it, and that alone disproves all the theories.

Ok, we got your assumptions out of the way, now for your question. The upper limit of natural elements is 92 protons: uranium. Heavier elements have been generated artificially, but they don't live long. It seems that protons and neutrons have to be in certain proportions, and as the numbers get larger it gets harder to find a combination that will be stable. We don't yet know what heavier elements are possible, or which isotopes won't hold together.

Actually the heaviest elements are formed during actual supernovae. Only elements as heavy as iron are formed in the cores of stars. The heaviest natural element we know of is plutonium. And it exists only in extremely small quantities in nature. In fact, it's so rare and unstable in nature that we had artificially produced plutonium before the first natural plutonium was ever found. We have synthetically produced elements as heavy as ununoctium, which is a full 24 protons heavier than plutonium. Is it possible that these elements heavier than plutonium, or even some heavier than ununoctium, exist elsewhere in the universe in nature and we just haven't discovered them? Sure it is. Obviously we have no idea what actually occurs inside a black hole and likely never will. But I would say no, elements could not be formed in a black hole. As we understand it even protons and neutrons would be torn apart in a black hole, and possibly the quarks even torn down further. Without at least protons and electrons elements can't exist. If they can't exist, they sure couldn't be formed.

Theoretically no, but it is impossible to prove that claim. You are probably aware of Palium principle, so mass/number of proton and neutrons is bound to rise. There is also 2 known "one place": metals and crystals. Just imagine that crystal is so big that it's mass it double of mass if it shattered. Force that would hold that crystal would be unimaginable (I don't know how much). It is quite natural that you would escape to black holes.

It is very easy to see what is going on "inside" Swartzchild radius. Just wait until light goes out of black hole (not talking about Hawking radiation).

What is atom? If atom is composed of electrons and protons then all we need is anti-neutrino to create neutron, so whole atom collapse. the effects are the same if atom is compressed into 0-D space or if neutron is. Though that perspective black hole is one atom. So your answer is "no, only one atom". There is another question: "element of what?". Can this mix where atomos are reveled (if such exist) really be organized into something that is element of something greater? It is good thing that I was able to form conclusion before we "reached" singularity, because singularity is point where nothing I know applies (I am not sure whether mathematics is able to speak about that point).

Lol SmartAZ you are quite challenged. just to address your last paragraph (which is most coherent one). If you know that elements above 92 aren't stable then how do you know they cannot be created naturally? Universe wields much more powerful forces that we can tame.

Actually only elements up to Iron can be formed by exothermic fusion (i.e. what happens in the core of star), you need supernova and some reactions in the atmosphere of other stars to form elements much beyond that (read up on r-process and s-process).

Heavier elements are extremely unstable with very short half lives and so don't last very long though it's possible that the extreme flux in a supernova would create some of them (thermonuclear bomb tests have created them, in fact Einsteinium and Fermium were first discovered in fallout).

So far the heaviest elements we've been able to make is ununoctium (temporary name, it'll get a better one later) and ununseptium (also a temporary name) which have isotopes with 294 nucleons..

There are many things which we still dont know the core of a blackhole is still a mystery so we exactly dont know what happens after the division of matter into the black holes. Yet matter cannot be created or destroyed it can transform so there must be matter in anyother form may be unknown if it is heavier then it can just get sinked coz there is no way out of blackhole its also possible that blackholes are links to parrallel world the negative universe so matter is released there in some other form .

That's a good question.

Unfortunately I'm sure the answer is no (as we understand it), because nuclei formed in stars are obviously the collection of protons and neutrons which take up space (volume) and as you have already mentioned the singularity of a BH in (in theory) is infinitesimally small. As matter is drawn into a BH the nuclei are pulled apart into P's & N's and then they themselves are pulled apart into Quarks. What happened after that? No one knows, but matter doesn't exist in a state to be able to form any form of predictable or recognizable nuclei. The laws of physics don't even apply as we know them, so it's really impossible to even guess.