Ionization

The ionization energy of some pure chemical elements. At the peaks are inert gases.

Ionization is the endothermic process of the formation of ions from neutral atoms or molecules .

A positively charged ion is formed if the electron in the molecule receives enough energy to overcome the potential barrier equal to the ionization potential . A negatively charged ion, on the contrary, is formed during the capture of an additional electron by an atom with the release of energy.

It is customary to distinguish between two types of ionization - sequential (classical) and quantum, not obeying some laws of classical physics .

Content

Classical ionization

Air ions, in addition to being positive and negative, are divided into light, medium and heavy ions. In its free form (at atmospheric pressure), an electron exists for no more than 10 ⁻⁷ - 10 ⁻⁸ seconds.

Electrolyte Ionization

Electrolytes are substances dissolved in water. Electrolytes include soluble salts , acids , metal hydroxides . In the process of dissolution, electrolyte molecules decompose into cations and anions . Faraday , relying on the data obtained from experiments with electrolysis , derived a formula on the proportionality of the mass m to the charge Δq, which passed through the electrolyte, or on the proportionality of the mass m to the current strength I and time Δt: $m=k\cdot \Delta q=k\cdot I\cdot \Delta t$ ${\ displaystyle m = k \ cdot \ Delta q = k \ cdot I \ cdot \ Delta t}$ .

Gaseous ionization

Gases are mostly composed of neutral molecules. However, if some of the gas molecules are ionized, the gas conducts an electric current. There are two main methods of ionization in gases:

Thermal ionization - ionization in which the necessary energy to detach an electron from an atom is provided by collisions between atoms due to an increase in temperature;
Ionization by an electric field - ionization due to an increase in the voltage value of the internal electric field above the limit value. From this follows the separation of electrons from gas atoms.
Ionization by ionizing radiation

Quantum ionization

In 1887, Heinrich Hertz established that, under the influence of light, electrons can escape from the body - a photoelectric effect was discovered. This was not consistent with the wave theory of light - it could not explain the laws of the photoelectric effect and the observed separation of energy in the spectrum of electromagnetic radiation . In 1900, Max Planck established that the body can absorb or emit electromagnetic energy only in special portions, quanta . This provided a theoretical basis for explaining the effects of the photoelectric effect. To explain the effects of the photoelectric effect, in 1905 Albert Einstein put forward a hypothesis about the existence of photons as particles of light, which allows us to explain the quantum theory - photons that are capable of being absorbed or emitted as a whole by an electron give it sufficient kinetic energy to overcome the force of gravity of the electron to the nucleus - quantum ionization occurs.

Ionization Methods

Methods used to ionize conductive materials:

Spark ionization : due to the potential difference between a piece of the test material and another electrode , a spark arises, tearing out ions from the target surface.

Ionization in a glow discharge occurs in a rarefied atmosphere of an inert gas (for example, in argon ) between the electrode and the conducting piece of the sample.

Impact ionization . If any particle with mass m (electron, ion or neutral molecule) flying at a speed V collides with a neutral atom or molecule, then the kinetic energy of the flying particle can be spent on the ionization act, if this kinetic energy is not less than the ionization energy .

Notes

↑ Woolston, Chris . It'll quench your thirst, of course. But whether ionized water can slow aging and fight disease is another matter , Los Angeles Times (January 22, 2007). Date of treatment October 30, 2008.

[latimes-1] Woolston, Chris . It'll quench your thirst, of course. But whether ionized water can slow aging and fight disease is another matter , Los Angeles Times (January 22, 2007). Date of treatment October 30, 2008.