Electrical charge, measurement

Wada, K, Sasaki, K and Masuhara, H. (2002) Electric charge measurement on a single microparticle using thermodynamic analysis of electrostatic forces. Appl. Phys. Lett., 81, 1768—1770. 

A type of angle-dependent x-ray photoemission spectroscopy was used to investigate the molecular orientation at the surface of sulfonated polystyrene as a function of reaction depth. A model based on these measurements indicates that at a critical sulfonation depth the aliphatic hydrocarbon backbone becomes exposed preferentially at the surface. These results are consistent with surface energy and tribo-electric charging measurements, which also reveal the effects of associative interactions in the form of conversion dependencies. 

The word electron was coined by G. Johnstone Stoney in 1891. It was used to describe a unit of electrical charge measured in his experiments where an electrical current was sent through various chemical solutions to test its effect. 

Electric flux The amount of electric charge, measured in coulombs, across a dielectric of specified area. Electric flux may also refer simply to electric lines of force. 

E. E. Donaldson, M. H. Miles, and J. T. Dickinson, Electrical charge measurements on ejecta from impact loading of explosive crystals, J. Mater. Sci. (to appear). 

A neutron is characterized by having no electrical charge but has one unit of atomic mass, the same as that of a proton (Figure 46.2). Neutrons, like protons, reside in the atomic nucleus and contribute to the mass of the atom. The chemistry of an atom, like its size, is determined by the electrons in the atom. The mass of the atom is characterized mainly by the total number of neutrons and protons in the nucleus (atomic binding energies are ignored in this discussion). For mass spectrometric purposes of measurement, it is the mass that is important in establishing m/z values. 

Polarizability Attraction. AU. matter is composed of electrical charges which move in response to (become electrically polarized in) an external field. This field can be created by the distribution and motion of charges in nearby matter. The Hamaket constant for interaction energy, A, is a measure of this polarizability. As a first approximation it may be computed from the dielectric permittivity, S, and the refractive index, n, of the material (15), where is the frequency of the principal electronic absorption... 

In 1903, Rutherford and associates were finally able to deflect the a-rays by electric and magnetic fields, showing that these are positively charged. Measurement of the charge-to-mass ratio indicated that a-rays were of atomic dimensions. In 1908 definitive experiments showed a-rays to be doubly chaiged helium atoms, ie, helium nuclei. 

The masses of the neutrinos have generally been considered to be exactiy 0, but modem theory and some more recent experiments suggest the masses may be non2ero, but stiU on the order of 1 eV. Because the neutrinos have such a small mass and no electrical charge, they interact primarily by the weak interaction. This means that their interaction probabiHty is very small and they typically pass through a mass as large as the earth without interacting. Therefore, they are not useful for any measurements related to radioactive decay. 

Electric field measurement at the boundary of a metal container filled with charged material. Examples include pipelines and storage vessels. The electric field can be used to calculate charge density (3-5.1). Eield meters can also be lowered into containers such as silos to determine the local fields and polarities. Quantitative interpretation of the reading requires correction for field intensification and is sometimes accomplished using computer simulations. 

Hays measured the current associated with electrically charged 99 p.m diameter particles of styrene divinylbenzene particles as these particles traversed gaps of 520 and 137 p.m separating two parallel electrodes. Based on these results. Hays [81 ] argued for the existence of locally charged patches on the particles. 

The quantity of electric charge is measured m coulombs, and the unit of electric current—the number of coulombs per second that go past any point— is the ampere (A), named after French physicist Andre Marie Ampere ... 

Most minerals in water exist as ions - electrically charged particles that give them an electrical conductivity. The different systems of units that measure their concentration can cause much confusion. For any calculation involving adding different ions to one another it is vital to use one of two systems of equivalents. 

We have dealt with electrolysis before—every time we discussed or measured the electrical conductivity of an electrolyte solution. To see this, let s consider the processes that occur when we cause electric charge to pass through an aqueous solution of hydrogen iodide. 

Molten lithium fluoride and sodium chloride have easily measured electrical conductivities. Nevertheless, these conductivities are lower than metallic conductivities by several factors of ten. Molten sodium chloride at 750°C has a conductivity about IQ-5 times that of copper metal at room temperature. It is unlikely that the electric charge moves by the same mechanism in molten NaCl as in metallic copper. Experiments show that the charge is carried in molten NaCl by Na+ and Cl- ions. This electrical conductivity of the liquid is one of the most characteristic... 

For an ideally polarizable electrode, q has a unique value for a given set of conditions.1 For a nonpolarizable electrode, q does not have a unique value. It depends on the choice of the set of chemical potentials as independent variables1 and does not coincide with the physical charge residing at the interface. This can be easily understood if one considers that q measures the electric charge that must be supplied to the electrode as its surface area is increased by a unit at a constant potential." Clearly, with a nonpolarizable interface, only part of the charge exchanged between the phases remains localized at the interface to form the electrical double layer. 

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