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
Passenger Movement Charge negative impact of the pilots' dispute of 1989. The departure tax was raised again in 1994 to A$25 to offset the additional cost of tourism promotion expenditure, specifically an additional A$80 million allocated to the development of new tourism products. Since its name change to passenger movement charge in 1995, the rate of the PMC has changed on several occasions. In most cases the Australian federal government has given a rationale for rate increases. Australia's departure tax is one of the highest in the world. Few jurisdictions levy taxes on departing international passengers, although some charge airport fees to cover