Pretty much. To simplify a bit: the most stable atom is iron-56 anything lighter can be fused and anything heavier can be split to release energy. Essentially after iron the forces that bind atoms together start to lose out to the repulsion between it's constituents, which makes heavier atoms more and more unstable.
This is also why stars that start to fuse iron together will start to cool down.
wesammikhail|3 years ago