Editing Hadean Eon (section)

=== Plasma ===
'''Plasma''', often referred to as the fourth state of matter, is a gas in which a certain proportion of the particles are '''ionized''' (meaning electrons have been separated from atoms) resulting in a mix of '''free electrons''' and '''ions'''. In the context of the ISM, plasma exists primarily in ionized regions such as HII clouds (described below; around hot stars where UV radiation is strong enough to ionize hydrogen). Plasma often has unique properties compared to neutral gases, such as being highly '''conductive''' to electricity and responsive to magnetic fields due to its '''charged''' particles.