(1) Proton - A constituent of an atomic nucleus with one unit positive (+1e) charge. (2) Electron - A constituent of an atom with one unit negative (-1e) charge. (3) Photon - A quantum of light/energy ( hf , h being planck's constant and f bing the frequency of radiation). (4) Phonon - A quantized mode of vibration occurring in a rigid crystal lattice, such as the atomic lattice of a solid (5) Gluon - An elementary particle that causes quarks to interact, and is indirectly responsible for the binding of protons and neutrons together in atomic nuclei. (6) Exciton - A quasiparticle formed by the combination of an electron and a positive hole which is free to move through a nonmetallic crystal as a unit. (7) Plasmon - A quasiparticle resulting from the quantization of plasma oscillations (8) Doppleron - A quantum of energy or momentum emitted or absorbed in the processes regarding the Doppler effect for atoms in the standing light wave. (9) Polaron - A quasiparticle composed of an electron and its accompanying polarization field. (10) Graviton - A postulated quantum that is thought to be the carrier of the gravitational field. (11) Magnon - A quasiparticle carrying a fixed amount of energy and lattice momentum, can be viewed as a quantized spin wave. (12) Tachyon - A hypothetical particle that travels at superluminal speed (>c) , first proposed by Arnold Sommerfeld. (13) Polariton - A quasiparticle resulting from strong coupling of electromagnetic waves with an electric or magnetic dipole-carrying excitation. (14) Ion - An ion is an atom or molecule which has lost (cation) or gained (anion) one or more valence electrons, giving it a positive or negative electrical charge.
Note: This was first written by me in THE NPS GOOGLE GROUP in May 06, 2008.