You searched for: “nuclei
nucleus (s), nuclei (pl)
1. The central portion of an atom which has a positive charge and contains most of the atom's mass.
2. A comet which has a chunk of solid matter at the center of a comet's head.
3. The central part of a spiral galaxy that is very dense with stars.
This entry is located in the following unit: Astronomy and related astronomical terms (page 17)