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Ionic potential is the ratio of the electrical charge (z) to the radius (r) of an ion. [1]= = As such, this ratio is a measure of the charge density at the surface of the ion; usually the denser the charge, the stronger the bond formed by the ion with ions of opposite charge.
The equation for local ion density can be substituted into the Poisson equation under the assumptions that the work being done is only electric work, and that the concentration of salt is much higher than the concentration of ions. [4] The electric work to bring an ion of charge to a surface with potential ψ can be represented by =. [4]
For example, from Fe 2+ + 2 e − ⇌ Fe(s) (–0.44 V), the energy to form one neutral atom of Fe(s) from one Fe 2+ ion and two electrons is 2 × 0.44 eV = 0.88 eV, or 84 907 J/(mol e −). That value is also the standard formation energy (∆ G f °) for an Fe 2+ ion, since e − and Fe( s ) both have zero formation energy.
The electrostatic interaction model of ions in solids has thus been extended to a point multipole concept that also includes higher multipole moments like dipoles, quadrupoles etc. [8] [9] [10] These concepts require the determination of higher order Madelung constants or so-called electrostatic lattice constants.
In solid-state physics, especially for metals and semiconductors, the screening effect describes the electrostatic field and Coulomb potential of an ion inside the solid. Like the electric field of the nucleus is reduced inside an atom or ion due to the shielding effect, the electric fields of ions in conducting solids are further reduced by ...
The electric potential and the magnetic vector potential together form a four-vector, so that the two kinds of potential are mixed under Lorentz transformations. Practically, the electric potential is a continuous function in all space, because a spatial derivative of a discontinuous electric potential yields an electric field of impossibly ...
Siméon Denis Poisson. Poisson's equation is an elliptic partial differential equation of broad utility in theoretical physics.For example, the solution to Poisson's equation is the potential field caused by a given electric charge or mass density distribution; with the potential field known, one can then calculate the corresponding electrostatic or gravitational (force) field.
The electrostatic potential energy, E pair, between a pair of ions of equal and opposite charge is: = where z = magnitude of charge on one ion e = elementary charge, 1.6022 × 10 −19 C ε 0 = permittivity of free space 4 π ε 0 = 1.112 × 10 −10 C 2 /(J·m)