Answer:
Protons and neutrons
Step-by-step explanation:
The particles to forms the nucleus of an atom are the protons and neutrons of the atoms.
These materials are located in the tiny nucleus and contributes the most mass of the atom.
- Protons are the positively charged particles in an atom
- Neutrons do not carry any charges.
- Sum of the protons and neutrons gives the mass number of the atom.