Here is a fun fact: only elements up to iron are produced as a result of fission. The rest, including elements essential to human life, elements in your body, are only produced through fusion. Fusion is known to only occur in stars. You are stars.
After the big bang and the expansion, and the condensation of energy into matter, the universe was almost entirely hydrogen and helium (i.e. extremely boring).
The heavier elements were fused together in the solar furnances (stars). The early stars were enormous, burnt through their fuel (walking up the Periodic Table to Iron) and then collapsed under the gravity pressure when the fuel ran out and exploded in a Supernovae. During these explosions a smattering of the heavier (than Iron) elements are fused together.
Our sun is a ~third generation star, made from the remains of other exploded stars.
So it's more that we are all star stuff; everything heavier than Iron (all the Lead, Tin, Iodine, radioactive elements, rare Earths etc.) are exploding star stuff.
Um not quite. Fission is where you break apart a heavy element like Uranium.
Fusion occurs in stars and the more massive the star the heavier the elements it can fuse in its core become. However fusing iron into heavy elements is ultimately a net loss in terms of outward pressure so the heaviest element you get from the fusion in the core of stars is iron. Heavier elements can only be synthesized in super nova.
