Answer:
Protons, and Neutrons.
Step-by-step explanation:
The nucleus of an atom is made up of protons, discovered in 1920 by Ernest Rutherford, and neutrons, discovered in 1932 by James Chadwick. Both protons and neutrons are like little spheres with a radius of 10 -15 m or a quadrillionth of a meter. Both particles are somehow stuck together in the nucleus.