Ionization in the context of "Ionizing radiation"

Plasma (from Ancient Greek πλάσμα (plásma)  'that which has been formed or moulded or the result of forming or moulding') is a state of matter that results from a gaseous state having undergone some degree of ionization. It thus consists of a significant portion of charged particles (ions and/or electrons). While rarely encountered on Earth, it is estimated that 99.9% of all ordinary matter in the universe is plasma. Stars are almost pure balls of plasma, and plasma dominates the rarefied intracluster medium and intergalactic medium. Plasma can be artificially generated, for example, by heating a neutral gas or subjecting it to a strong electromagnetic field.

The presence of charged particles makes plasma electrically conductive, with the dynamics of individual particles and macroscopic plasma motion governed by collective electromagnetic fields and very sensitive to externally applied fields. The response of plasma to electromagnetic fields is used in many modern devices and technologies, such as plasma televisions or plasma etching.

An aurora (pl. aurorae or auroras) is a natural light display in Earth's sky, predominantly observed in high-latitude regions around the Arctic and Antarctic. The terms northern lights (aurora borealis) and southern lights (aurora australis) are used in the Northern and Southern Hemispheres respectively. Auroras display dynamic patterns of radiant light that appear as curtains, rays, spirals or dynamic flickers covering the entire sky.

Auroras are the result of disturbances in the Earth's magnetosphere caused by enhanced speeds of solar wind from coronal holes and coronal mass ejections. These disturbances alter the trajectories of charged particles in the magnetospheric plasma. These particles, mainly electrons and protons, precipitate into the upper atmosphere (thermosphere/exosphere). The resulting ionization and excitation of atmospheric constituents emit light of varying colour and complexity. The form of the aurora, occurring within bands around both polar regions, is also dependent on the amount of acceleration imparted to the precipitating particles.

An interstellar cloud is an accumulation of gas, plasma, and cosmic dust in galaxies. Put differently, an interstellar cloud is a denser-than-average region of the interstellar medium, the matter and radiation that exists in the space between the star systems in a galaxy. Depending on the density, size, and temperature of a given cloud, its hydrogen can be neutral, making an H I region; ionized, or plasma making it an H II region; or molecular, which are referred to simply as molecular clouds, or sometime dense clouds. Neutral and ionized clouds are sometimes also called diffuse clouds. An interstellar cloud is formed by the gas and dust particles from a red giant in its later life.

An astrophysical jet is an astronomical phenomenon where ionised matter is expelled at high velocity from an astronomical object, in a pair of narrow streams aligned with the object's axis of rotation. When the matter in the beam approaches the speed of light, astrophysical jets become relativistic jets as they show effects from special relativity.

Astrophysical jets are associated with many types of high-energy astronomical sources, such as black holes, neutron stars and pulsars. Their causes are not yet fully understood, but they are believed to arise from dynamic interactions within accretion disks. One explanation is that as an accretion disk spins, it generates a rotating, tangled magnetic field which concentrates material from the disk into the jets and then drives it away from the central object. Jets may also be influenced by a general relativity effect known as frame-dragging.

Acid strength is the tendency of an acid, symbolised by the chemical formula HA, to dissociate into a proton, H, and an anion, A. The dissociation or ionization of a strong acid in solution is effectively complete, except in its most concentrated solutions.

Examples of strong acids are hydrochloric acid (HCl), perchloric acid (HClO₄), nitric acid (HNO₃) and sulfuric acid (H₂SO₄).

Amino acids are organic compounds that contain both amino and carboxylic acid functional groups. Although over 500 amino acids exist in nature, by far the most important are the 22 α-amino acids incorporated into proteins. Only these 22 appear in the genetic code of life.

Amino acids can be classified according to the locations of the core structural functional groups (alpha- (α-), beta- (β-), gamma- (γ-) amino acids, etc.); other categories relate to polarity, ionization, and side-chain group type (aliphatic, acyclic, aromatic, polar, etc.). In the form of proteins, amino-acid residues form the second-largest component (water being the largest) of human muscles and other tissues. Beyond their role as residues in proteins, amino acids participate in a number of processes such as neurotransmitter transport and biosynthesis. It is thought that they played a key role in enabling life on Earth and its emergence.

The ionosphere (/aɪˈɒnəˌsfɪər/) is the ionized part of the upper atmosphere of Earth, from about 48 km (30 mi) to 965 km (600 mi) above sea level, a region that includes the thermosphere and parts of the mesosphere and exosphere. The ionosphere is ionized by solar radiation. It plays an important role in atmospheric electricity and forms the inner edge of the magnetosphere. It has practical importance because, among other functions, it influences radio propagation to distant places on Earth. Travel through this layer also impacts GPS signals, resulting in effects such as deflection in their path and delay in the arrival of the signal.

Atmospheric science is the study of the Earth's atmosphere and its various inner-working physical processes. Meteorology includes atmospheric chemistry and atmospheric physics with a major focus on weather forecasting. Climatology is the study of atmospheric conditions over timescales longer than those of weather, focusing on average climate conditions and their variability over time. Aeronomy is the study of the upper layers of the atmosphere, where dissociation and ionization are important. Atmospheric science has been extended to the field of planetary science and the study of the atmospheres of the planets and natural satellites of the Solar System.

Experimental instruments used in atmospheric science include satellites, rocketsondes, radiosondes, weather balloons, radars, and lasers.