Quiz On Atoms For 4th, 5th And 6th Grade Kids. Learn about parts of an atom and their functions, electron, nucleus, neutron, proton, electron shell etc. Electrons have a negative charge, protons a positive charge while neutrons are neutral. Electrons revolve around an atom along an electron shell. Each atom has a specific number of electrons and protons. In this quiz fifth graders will review their skills on atoms. Practice and share.