If you are referring to Nucleus.
Nucleus (Chemistry)
The central part of an atom, containing protons and electrons.
Nucleus (Biology)
A cell organelle that is only present on eukaryotic cells, that functions as the brain of the cell, it contains Deoxyribonucleic Acid or DNA, and the Nucleolus that serves as the factory for ribosome synthesis, to translate mRNA into Protein.
