Answer: The correct option is (C).
Explanation:
An atom is a smallest unit of the matter. Atom consists of electrons, protons, nucleus and neutrons.
Nucleus is the central part of the atom where the whole mass of the atom is supposed to be concentrated.
The electrons revolve around the nucleus. They are negatively charged particle.
The protons are located in the nucleus. They are positively charged particle.
The neutrons are located in the nucleus. They are neutral charged particle.
Therefore, an atom nucleus is the central part of an atom, composed of protons and neutrons.
