The atomic nucleus is made up of two particles that are protons and neutrons.
Answer: Option B.
Explanation:
The atom has the core part as the nucleus in the center part of the atom. The nucleus consists of two particles. These are namely, protons and neutrons.
Proton contains a positive charge but whereas the neutron does not have any charges; therefore, the nucleus acquires the positive charge of the proton. Both of them together constitute the atomic mass and the mass number.