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atom
atom
Fundamental unit of matter having unique chemical properties; it is composed of a nucleus and an electron cloud. One atom is distinguished from another by the number of protons in its nucleus.
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proton
Constituent particle of an atom’s nucleus whose electric charge is positive; it is composed of two u quarks and one d quark.
proton
electron
Particle having a negative electric charge that revolves around the nucleus of the atom.
nucleus
Central part of the atom whose electric charge is positive; it is composed of protons and neutrons, around which electrons revolve.
neutron
Constituent particle of an atom’s nucleus whose electric charge is neutral; it is composed of one u quark and two d quarks.
neutron