Ask A Scientist Chemistry Archive

From:       novak
Text:       We are studying matter.  The students want to know if there are 3 
or 4 states of matter.  What would fire be considered?

Response #:  1 of 1
Author:      Joe Schultz
Text:        First, fire is not a state of matter...it is a form of energy.  
It is heat energy and light energy together (with some sound energy thrown in 
too maybe).  The three states of matter are solid, liquid, and gas.  A fourth 
state of matter that I believe has been proposed, if not already accepted, is 
a plasma.  A plasma is essentially a really hot, ionized gas.  It looks like a 
flame but there is nothing burning.  Temperatures of a plasma could get up to 
10,000 K (9727 degrees C or 17500 degrees F).  Analytical instruments 
currently use these plasmas as sources to excite atoms (I use one in my 
research).