Re: Why does a candle blow out if oxygen is needed to burn?

Lucas, you are right in saying that oxygen is needed in order for a candle 
to burn.  However, the breath reduces or "thins out" some other things 
that the flame needs in order to keep burning.  One of these things is a 
certain amount of heat to keep the burning process alive.  When you blow 
on the candle, the breath absorbs and carries away this needed heat.  
Another thing is fuel.  The breath carries away small particles 
(molecules) of the fuel (the paraffin vapor).  The flame needs both the 
heat and fuel, but the breath has significantly reduced both so that the 
candle flame is extinguished.

Keep up the good observations and questions!

Sincerely,
Charles Riner
Motaatom@aol.com