Keep in mind I have not studied fluid dynamics or plasma stuff at all... Now, both gases and liquids are fluids. Is a plasma an ionised gas, or an ionised fluid? The reason I ask is because the big difference between the gas and liquid forms of various things is the amount of energy. Is the amount of energy involved the deciding factor of whether something is a plasma or not? If you apply a charge to the neon in a light, it is a plasma. But what if that neon is cooled to liquid, then a charge is applied? Basically I'm looking for a definition of plasma that covers the difference between liquid and gas. Thanks.