a nucleus is the center of a cell that controls the organelles inside a cell.
eat banana cream pie
Roots, leaves, flowers and fruit. The fruit carries the seed on the outside.
It seems you may be referring to "neculus," which is not a recognized term in common contexts. If you meant "nucleus," it is the central part of an atom that contains protons and neutrons, or the control center of a cell that houses genetic material. If you meant something else, please provide more context for clarification!
After the nucleus break down, the atoms become smaller in some way. The remaining atom may be radioactive or it can also be balanced. The end result during the disintegration may be known depends on the process of how it disintegrates.