Electrons move around the nucleus in special paths calledelectron shells (orbits/or orbitals or energy levels). Protons andelectrons have electric charges. Neutrons have no charges.All the particles in an atom are very light. Their masses aremeasured in atomic mass units rather than grams.
The proton isa positively charged particle. Its mass is about equal to that ofhydrogen atom. The neutron is has no charge, it is neutral. Itsmass is about equal to that of hydrogen atom. The electron isnegatively charged. Its charge is equal but opposite to the chargeon the proton. It has a very small mass, about 1⁄1840 of the massof the proton.
The Properties of each Particle in an Atom