" For example, the electron and the muon both have half-integer spin and unit electric charge, but the muon is about 200 times more massive. The electron and the electron-neutrino, and their counterparts in the other generations, are called "leptons", "weakly interacting particles" . Unlike the quarks, they do not possess a quality called "color", and their interactions are only weak and electromagnetic, and fall off with distance. On the other hand, the strong or "color" force between quarks gets stronger with distance, so that quarks are always found in colorless combinations called hadrons, a phenomenon known as quark confinement. These are either fermionic baryons composed of three quarks (the proton and neutron being the most familiar example) or bosonic mesons composed of a quark-antiquark pair (such as pions). The mass of such aggregates exceeds that of the components due to their binding energy. Tests and predictions The Standard Model predicted the existence of W and Z bosons, the gluon, the top quark and the charm quark before these particles had been observed. Import Model Christine Mendoza Their predicted properties were experimentally confirmed with good precision. The Large Electron-Positron collider at CERN tested various predictions about the decay of Z bosons, and found them confirmed. "

" (Eds. ) Professional knowledge management; LNCS 3782 Springer Verlag; 2005. Models as people artist model — in art school modeling, a person who poses for purposes of art. model — person whose occupation is to display clothing (eg. a "fashion model") or other personal items of artistic or aesthetic value, and who is often physically attractive; a model who attains celebrity status or is otherwise widely known is said to be a "supermodel". promotion model— promotes a product or service role model — person who acts as a behavioural or moral example to others. Models as physical objects physical model — physical representation of an object; in engineering, similitude is used in the scientific testing of physical models. Asian Import Model Wallpaper scale model — a replica or prototype of an object built as a hobby or for research. a particular version of a series of vehicles produced by an automobile manufacturer is known as a model. "