Point particle of point charges cannot be maintained in an equilibrium configuration solely by the electrostatic interaction of the charges. In quantum mechanics, there is a distinction between an elementary particle (also called "point particle") and a composite particle. An elementary particle, such as an electron, quark, or photon, is a particle with no internal structure. Whereas a composite particle, such as a proton or neutron, has an internal structure (see figure). However, neither elementary nor composite particles are spatially localized, because of the Heisenberg uncertainty principle. The particle wavepacket always occupies a nonzero volume. For example, see atomic orbital: The electron
Graham (given name) Graham (given name) Graham () is a masculine given name in the English language. According to some sources, it comes from an Old English word meaning "grey home". According to other sources, it comes from the surname "Graham", which in turn is an Anglo-French form of the name of the town of Grantham, in Lincolnshire, England. The settlement is recorded in the 11th century "Domesday Book" variously as "Grantham", "Grandham", "Granham" and "Graham". This place name is thought to be derived from the Old English elements "grand", possibly meaning "gravel", and "ham", meaning "hamlet" the English word given to small