Almost every matter can change phase from state to liquid and gas and all of it depends of the temperature. But I guess you call Argon "a true gas" because it has gas phase in a room temperature, right? Ok, you want to go there True gases are molecules not ions, O2, N2, CO2, Argon, Neon and they occur naturally as gas, you can't see them and most make up air. A gas also has a perfect molecular mobility and the indefinite property of expansion A vapor is not a gas really, it is quantity of visible matter diffused or suspended in air and air is made of gases. Vapors may occur as molecule or ions. Vapor does not =gas and gas does not = vapor Thus water or Mercury are not gases but vapors and using the term "gas" is using it loosely and not by its proper meaning . However, some do choose to do so but it is incorrect. You know what a MV lamp is, Mercury Vapor, it is not called a MG lamp because it is not a gas. Air does not have water gas in it, it is always called water vapor and there is a reason for that, it is not a gas. Think of vapor as a very find dust "But some of missunderstanding here can be derived from the fact, that English is my second language, as it was stated correctly on this ng recently )" I did not know that where are you from ? "Do I understand correctly you are saying design of gas discharge lamps are your profession?" No you do not understand correctly. Go back and re-read it. I said I know the guy that invented the tri-phosphor lamps, his name is Dr Perry Thrasher -- Boomer Want to talk chemistry ? The Reef Chemistry Forum http://www.reefcentral.com/vbulletin/index.php Want to See More ? Please Join Our Growing Membership www.coralrealm.com If You See Me Running You Better Catch-Up "Pszemol" <Pszemol@PolBox.com> wrote in message news:firstname.lastname@example.org... : "Boomer" <email@example.com> wrote in message news:firstname.lastname@example.org... : > "I was not talking about Argon but about "gases in the tube" )" : > : > OK, I'll let you off the hook since you say ""gases in the tube" , in which case the only : > real "gas" is Mercury vapor and only Mercury vapor, with the very very small addition of : > some of he emissive material being "gases". : : Ok, thank you for your mercy ;-) : : > Aragon is a true gas and not a vapor. : : I do not like the "true gas" term... How do you define it? : Gas is gas There is no true gas or false gas ) : Almost every matter can change phase from state to liquid and gas : and all of it depends of the temperature. But I guess you call Argon : "a true gas" because it has gas phase in a room temperature, right? : : > One other thing; : > : > "Plasma is ionized gas ))" : > : > Well, that is only half of it. ) A Plasma is a stream of positively charged : > ions accompanied by about equal proportions of electrons : : By "ionized gas" I ment whole gas in state of ionizations. : No ions alone, but with electrons detached from original atoms too : But some of missunderstanding here can be derived from the fact, : that English is my second language, as it was stated correctly : on this ng recently ) : : > "I was also correct with the three-phosphors tubes " : > : > I know the guy personnel, that invented all of the tri lamps with the built in reflectors, : > Dr. Perry Thrasher, know matter what name is on the bulb. Perry has left the company ,do : > to illness and I haven't found out where he went other than California for health reasons. : > Me and JB ( John Burleson) had the first sets : > : > http://www.light-sources.com/ : : Do I understand correctly you are saying design of gas discharge lamps are your profession?