ion, ion- +

1. The fractional degree of ionization of acids, bases, or salts that has taken place in a solution or reaction mixture.
2. The proportion of potential ionization that has taken place for an ionizable material in a solution or reaction mixture.

1. The amount of energy required to remove an electron from a specific atom or ion to an infinite point, generally expressed in electron volts and numerically equal to the ionization potential.
2. The energy required o remove completely the weakest bound electron from its ground state in an atom or molecule so that the resulting ion is also in its ground state.
3. Amount of energy required to remove an electron from an isolated atom or molecule.

There is an ionization potential for each successive electron removed, though that associated with removing the first (most loosely held) electron is most commonly used.

The ionization potential of an element is a measure of its ability to enter into chemical reactions requiring ion formation or donation of electrons and is related to the nature of the chemical bonding in the compounds formed by elements.

1. In astrophysics, a region in space in which the interstellar gas, commonly hydrogen, changes from a mostly neutral state to a mostly ionized situation, because of the ultraviolet radiation from hot stars nearby.
2. A transition region that separates interstellar gas in which a given atomic species, usually hydrogen, is mostly ionized from interstellar gas in which it is essentially neutral.

An instrument for x-ray analysis of crystal structure and measuring wavelengths of X-rays and gamma rays, in which a homogeneous beam of X-rays is directed on the known face of a crystal and the reflected beam is detected in a suitably placed ionization chamber.

A class of techniques in crystal spectroscopy wherein an ionization chamber (an X-ray detector) is appropriately placed to detect the reflected X-rays after undergoing Bragg scattering which is the scattering of X-rays or neutrons by the regularly spaced atoms in a crystal, for which constructive interference occurs only at definite angles called Bragg angles (angles between an incident X-ray beam and a set of crystal planes for which the secondary radiation displays maximum intensity as a result of constructive interference).

"Bragg scattering" and "Bragg angles" are named after, Sir William Henry Bragg (1862–1942), and his son, Sir William Lawrence Bragg (1890–1971); English physicists and Nobel prize winners in 1915.

1. The amount of time it takes for a gaseous substance to ionize after an ionizing property has been applied to it.
2. Referring to a gas tube, the time interval between the initiation of conditions for and the establishment of conduction at some stated value of tube voltage drop.

To undergo or to cause to undergo ionization.

1. Any atom with more or fewer electrons than protons, resulting in a net charge.
2. An atom with an excess or deficiency of electrons, so that it has a net charge.

The ionized, unbound, non-complexed fraction of serum calcium that is biologically active.

1. A gas composed partially or totally of ions; such as, a plasma.
2. A gas, with some atoms or molecules that have undergone ionization.
3. A gas in which a certain portion of the particles are ionized.

1. The layers of enhanced ionization produced within the ionosphere by impinging, or bringing together, cosmic radiation.
2. Layers of increased ionization within the ionosphere produced by cosmic radiation; responsible for absorption and reflection of radio waves and important in connection with communications and tracking of satellites and other space vehicles.

The average energy lost by ionizing radiation in producing an ion pair in a gas.

In air the value is approximately 33.73 electron volts.

1. Any event in which ionization occurs, commonly caused when an electron or a photon with sufficient energy passes through a sample of matter.
2. Any occurrence in which an ion or group of ions is produced; for example, by passage of charged particles through matter or the passage of alpha or beta particles or gamma rays through a gas.

Damage or ill effects suffered by exposure to ionizing radiation, including cellular harm resulting from radiation for diagnostic or therapeutic applications.

The risk of cell death or injury from radiation depends on the type of tissue cells, the stage of cell division at the time of exposure, the intensity and time span of exposure, and the type of radiation administered.

1. High-energy radiation capable of producing ionization in substances through which it passes.

It includes non-particulate radiation; such as. X-rays, and radiation produced by energetic charged particles; such as, alpha and beta rays, and by neutrons, as from a nuclear reaction.

2. Particulate or electromagnetic radiation that produces ionization in a medium through which it passes.
3. Any radiation; such as, a stream of alpha particles or x-rays, that produces ionization as it passes through a medium.
4. Particles or photons that have sufficient energy to produce ionization directly in their passage through a substance.
5. Particles that are capable of nuclear interactions in which sufficient energy is released to produce ionization.
6. Photons of high-energy electromagnetic radiation and particle forms of radiation that have sufficient energy to produce ions by removing electrons from atoms or molecules.