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These two examples show that an electrical potential and a chemical potential can both give the same result: A redistribution of the chemical species. Therefore, it makes sense to combine them into a single "potential", the electrochemical potential , which can directly give the net redistribution taking both into account.
The abstract definition of chemical potential given above—total change in free energy per extra mole of substance—is more specifically called total chemical potential. [13] [14] If two locations have different total chemical potentials for a species, some of it may be due to potentials associated with "external" force fields (electric ...
Diagram of ion concentrations and charge across a semi-permeable cellular membrane. An electrochemical gradient is a gradient of electrochemical potential, usually for an ion that can move across a membrane. The gradient consists of two parts: The chemical gradient, or difference in solute concentration across a membrane.
An important example is the formation of adenosine triphosphate (ATP) by the movement of hydrogen ions (H +) across a membrane during cellular respiration or photosynthesis. An ion gradient has potential energy and can be used to power chemical reactions when the ions pass through a channel (red).
An example of a proton pump that is not electrogenic, is the proton/potassium pump of the gastric mucosa which catalyzes a balanced exchange of protons and potassium ions. [ citation needed ] The combined transmembrane gradient of protons and charges created by proton pumps is called an electrochemical gradient .
Under the free electron model, the electrons in a metal can be considered to form a Fermi gas. The number density N / V {\displaystyle N/V} of conduction electrons in metals ranges between approximately 10 28 and 10 29 electrons/m 3 , which is also the typical density of atoms in ordinary solid matter.
The equation describes the motion of a fictitious particle of mass equal to the reduced mass of the two nuclei, in the potential E tot (R)+V L (R), where the second term is the centrifugal potential due to rotation with angular momentum described by the quantum number L. The eigenenergies of this Schrödinger equation are the total energies of ...
The ionization energy is the minimum amount of energy that an electron in a gaseous atom or ion has to absorb to come out of the influence of the attracting force of the nucleus. It is also referred to as ionization potential. The first ionization energy is the amount of energy that is required to remove the first electron from a neutral atom.