Plasma is one of four fundamental states of matter characterized by the presence of a significant portion of charged particles in any combination of ions or electrons. It is the most abundant form of ordinary matter in the universe, mostly in stars, but also dominating 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.
Lightning as an example of plasma present at Earth's surface: Typically, lightning discharges 30 kiloamperes at up to 100 megavolts, and emits radio waves, light, X- and even gamma rays. Plasma temperatures can approach 30000 K and electron densities may exceed 1024 m−3.
Artificial plasma produced in air by a Jacob's Ladder
Hall-effect thruster
Plasma spraying
In physics, a state of matter is one of the distinct forms in which matter can exist. Four states of matter are observable in everyday life: solid, liquid, gas, and plasma. Many intermediate states are known to exist, such as liquid crystal, and some states only exist under extreme conditions, such as Bose–Einstein condensates and Fermionic condensates, neutron-degenerate matter, and quark–gluon plasma. For a list of exotic states of matter, see the article List of states of matter.
Bromine in both liquid and gas state, encased inside acrylic in solid state
Helium's orange glow in its plasma state
Artificial plasma produced in air by a Jacob's Ladder. The extremely strong potential difference between the two rods ionize particles in the air, creating a plasma.
SBS block copolymer in TEM