ion, ion- +

(Greek: ion, "going"; neuter present participle of ienai, "to go"; because an ion moves toward the electrode of an opposite charge)

The electrical charging of particulate matter in the air, as for therapeutic use by inhalation.
atmospheric ionization (s) (noun), atmospheric ionizations (pl)
1. The process by which neutral atmospheric molecules or atoms are rendered electrically charged chiefly by collisions with high-energy particles.
2. The charging of neutral particles in the atmosphere through violent contact with charged particles.
3. The production of ions in the atmosphere by the loss of an electron from a molecule, typically, for example, by cosmic rays or cosmic radiation.

Cosmic rays and radioactive decay are the main sources of atmospheric ionization.

Radioactivity at the surface can also produce ions in the lowest layer of the atmosphere.

avalanche ionization, Townsend avalanche, Townsend ionization
A process occurring among gaseous ions in an ionization chamber radiation detector.

Given an adequate mean free path, a primary ion caused by the incident radiation can be accelerated by the applied voltage to the point where its collisions produce several other ions, where each secondary ion does the same thing, and so on, causing an "avalanche".

The multiplication of ions can be in the millions or more.

carbonium ion
Any member of a class of organic molecules with positive charges localized at a carbon atom.

Certain carbonium ions can be prepared in such a way that they are stable enough for study; more frequently they are only short-lived forms (intermediates) occurring during chemical reactions.

Carbonium ions are, in fact, one of the most common classes of intermediates in organic reactions, and knowledge of the structures and properties of these substances is fundamental to understanding reactions in which they occur.

Many of these reactions are of synthetic, biochemical, or industrial importance.

—Compiled from "carbonium ion", Encyclopædia Britannica; 2010;
Encyclopædia Britannica Online; May 22, 2010.
dipolar ion
A molecular entity carrying charges of opposite signs.
heavy ion
In nuclear physics, any particle with one or more units of electric charge and a mass exceeding that of the helium-4 nucleus (alpha particle).

Special types of accelerators are capable of producing fairly intense, high-energy beams of heavy ions, which are used in basic research, as in the production of synthetic transuranium elements (for example, hahnium [atomic number 105]).

—Compiled from "heavy ion", Encyclopædia Britannica; 2010;
Encyclopædia Britannica Online; May 22, 2010.
hydrogen ion
The nucleus of a hydrogen atom separated from its accompanying electron.

The hydrogen nucleus is made up of a particle carrying a unit positive electric charge, called a proton.

Because the bare nucleus can readily combine with other particles (electrons, atoms, and molecules), the isolated hydrogen ion can exist only in a nearly particle-free space (high vacuum) and in the gaseous state.

In common usage, the term hydrogen ion is used to refer to the hydrogen ion present in water solutions, in which it exists as the combined molecule H + H2O.

The amount of hydrogen ion present in a water solution is used as a measure of the acidity of a substance; the higher the concentration of hydrogen ion the more acidic the solution and the lower the pH.

—Compiled from "hydrogen ion", Encyclopædia Britannica; 2010;
Encyclopædia Britannica Online; May 22, 2010.
1. An atom, or atoms, a radical, or a molecule, having a negative or positive electric charge; that has gained or lost one or more electrons and thus acquired a net negative or positive charge.

In electrolysis, positive ions (cations) travel to the cathode, while negative ions (anions) travel to the anode.

2. An atom from which one or more electrons have been torn off, leaving a positively charged particle.

Negative ions are atoms which have acquired one or more extra electrons, and clusters of atoms can also become ions.

3. Etymology: from 1834, introduced by English physicist and chemist Michael Faraday, coined from Greek ion, neuter, present participle of ienai, "to go".
ion accelerator
1. A machine in which an electric field produced by external oscillators or amplifiers propels electrons in a straight to produce a beam of highly charged particles.
2. A linear accelerator in which ions are accelerated by an electric field in a standing-wave pattern that is set up in a resonant cavity by external oscillators or amplifiers.
ion atmosphere
A cloud-like configuration of ions that are loosely bound around an ion of the opposite charge.
ion backscattering
1. Large-angle elastic scattering of monoenergetic ions in a beam directed at a metallized film on silicon or some other thin multilayer system.
2. The scattering in a nearly backward direction of an ion beam incident on a film or body.
ion beam fusion
In nuclear energy, a method of internal confinement fusion in which an energy beam of electrons or other particles is directed onto a tiny pellet of a deuterium-tritium mixture, causing it to explode like a miniature hydrogen bomb, fusing the deuterium and tritium nuclei within a time span too short for them to repel each other.
ion burn, ion spot
A cathode-ray tube screen, an area of localized deterioration of luminescence caused by bombardment with negative ions.
ion channel, ionic channel
1. A trans-membrane protein structure that forms an aqueous pore that allows only certain ion species to pass through the membrane.
2. A trans-membrane pore that presents a hydrophilic (dissolve in or mix with water) channel for ions to cross a lipid bilayer (layer two molecules thick) down their electrochemical gradients.
3. Protein expressed by virtually all living cells that creates a pathway for charged ions from dissolved salts, including sodium, potassium, calcium, and chloride ions, to pass through the otherwise impermeant lipid cell membrane.

Operation of cells in the nervous system, contraction of the heart and of skeletal muscle, and secretion in the pancreas are examples of physiological processes that require ion channels. In addition, ion channels in the membranes of intracellular organelles are important for regulating cytoplasmic calcium concentration and acidification of specific subcellular compartments

Ongoing basic research on ion channels seeks to understand the structural basis for permeability, ion selectivity, and gating at the molecular level.

Research efforts also attempt to answer questions about the cellular regulation of ion channel protein synthesis and about the subcellular distribution and ultimate degradation of channels.

In addition, compounds with greater specificity and potency for channels involved in pain sensation, cardiovascular disease, and other pathological conditions are potential sources for drug development.

—Compiled from "ion channel", Encyclopædia Britannica; 2010;
Encyclopædia Britannica Online; May 22, 2010.
ion cloud
A region of enhanced ion density in the atmosphere, often occurring in the E layer.

A cross reference of word units that are related, directly and/or indirectly, with "electricity": electro-; galvano-; hodo-; piezo-; -tron; volt; biomechatronics, info; mechatronics, info.