Correct Answer: Proton, and Neutron

Solution : The correct options are Proton and Neutron.

An atom's nucleus is made up of Protons and Neutrons. Neutrons are neutrally charged particles, whereas Protons are positively charged ones. The strong nuclear force, which overcomes the repulsive electromagnetic attraction between positively charged protons, holds these particles together. Negatively charged electrons orbit around the nucleus in electron shells or energy levels. The atomic number is the number of Protons in the nucleus that establishes the element's identity. The mass number is the sum of Protons and Neutrons in the nucleus.