|MadSci Network: Chemistry|
The transition from a gas to a plasma is called ionization. There is some disagreement on whether or not the transition from a gas to a plasma is a true phase change. The answer depends on how you define a phase change. Some feel that there are only three states of matter: solids, liquids, and gases. They hold that plasma is not a new state of matter, but rather is an ionized gas. Thus, in this view, plasma is just a special case of the gas phase.
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