Editing State of matter (section)

===Plasma===
{{Main|Plasma (physics)}}
[[File:Plasma jacobs ladder.jpg|thumb|Artificial plasma produced in air by a [[Electric arc#Visual entertainment|Jacob's Ladder]]. The extremely strong [[potential difference]] between the two rods [[ionize]] particles in the air, creating a plasma.]]

A gas is usually converted to a plasma in one of two ways, either from a huge voltage difference between two points, or by exposing it to extremely high temperatures. Heating matter to high temperatures causes electrons to leave the atoms, resulting in the presence of free electrons. This creates a so-called partially ionised plasma. At very high temperatures, such as those present in stars, it is assumed that essentially all electrons are "free", and that a very high-energy plasma is essentially bare nuclei swimming in a sea of electrons. This forms the so-called fully ionised plasma.

The plasma state is often misunderstood, and although not freely existing under normal conditions on Earth, it is quite commonly generated by either [[lightning]], [[electric spark]]s, [[Fluorescent lamp|fluorescent lights]], [[Neon sign|neon lights]] or in [[Plasma display|plasma televisions]]. The [[solar corona|Sun's corona]], some types of [[flame]], and stars are all examples of illuminated matter in the plasma state. Plasma is by far the most abundant of the four fundamental states, as 99% of all [[ordinary matter]] in the universe is plasma, as it composes all [[stars]].<ref>{{Cite web |date=Sep 7, 1999 |title=Plasma, Plasma, Everywhere |url=https://science.nasa.gov/science-news/science-at-nasa/1999/ast07sep99_1 |website=NASA Science}}</ref><ref>{{Cite book |last=Aschwanden, M. J. |title=Physics of the Solar Corona. An Introduction. |publisher=Praxis Publishing |year=2004 |isbn=978-3-540-22321-4}}</ref><ref>{{Cite book |last=Piel |first=Alexander |url=https://books.google.com/books?id=9cA0DwAAQBAJ&pg=PR8 |title=Plasma Physics: An Introduction to Laboratory, Space, and Fusion Plasmas |date=2017-09-07 |publisher=Springer |isbn=978-3-319-63427-2 |language=en}}</ref>