A friend stated that stars are hot balls of gas, however we know that technically stars are plasma. Is his statement entirely incorrect? Can a plasma be considered a form of gas or should be referred to as a distinct form of matter?
Astrophysics – What’s the Difference Between Gas and Plasma?
astrophysicsplasma-physicsstates-of-matter
Best Answer
Good question! The defining difference is that in a gas the atoms are intact, and in fact are typically bonded into molecules, whereas in a plasma at least some of the electrons separate entirely from their atoms. In other words, particles of a plasma are charged, but particles of a gas are mostly uncharged. So technically, a plasma is not a gas and it should be said that a star is a ball of plasma, not gas. (Actually, there is a thin outer layer called the photosphere which actually consists of gas because the temperature isn't hot enough to form plasma)
However, outside of physics, people often use the word "gas" to refer to any sort of vaporous substance, and in that sense I suppose a plasma counts. So there is a sense in which your friend's statement might be considered correct. But that's a question for the English site.