Comparing the Three Subatomic Particles

Comparing the three subatomic particles means matching each one's location, charge, and relative mass, since sorting these three properties correctly is what most other atomic reasoning depends on.

Protons and neutrons both sit in the nucleus and carry roughly the same mass as each other; protons carry one positive unit of charge, neutrons carry none. Electrons sit outside the nucleus, occupying nearly all of an atom's volume despite carrying almost none of its mass — a proton or neutron outweighs an electron by more than a thousand times. Charge tells positive from negative: protons positive, electrons negative, neutrons neutral. Location tells nucleus from surrounding space: protons and neutrons inside, electrons outside. A neutral atom of any element always has as many electrons as protons, which is what keeps the whole atom electrically balanced despite holding two other kinds of particles with opposite charges packed into its tiny core.