How are protons, neutrons, and electrons similar?
These are all the fundamental particles of matter.
Protons are massive, positively charged nuclear particles. Neutrons are massive, neutrally charged nuclear particles. You are no doubt aware that together, the protons and neutrons form the nucleus, the massive elemental core, which is held together by the strong nuclear force, a short range force that is greater than the electrostatic force of repulsion. So much for
Orbiting the nucleus, are various numbers of electrons, fundamental particles of negligible mass, but of opposite electronic charge to the proton. The sharing and transfer of electrons between atoms, results in chemical bonding, and the formation of ions, and molecules.
Knowledge of the fundamental particles, neutrons, protons, and electrons, thus underpins current understanding of chemistry and physics.