* Fire is a process, not a substance: Fire is a chemical reaction, specifically combustion. It involves the rapid reaction between a fuel source (like wood or gas) and an oxidant (usually oxygen).
* Fire involves matter in transformation: During combustion, the fuel and oxygen are transformed into different substances, primarily carbon dioxide, water, and ash. These are all forms of matter.
* Fire has mass and takes up space: The smoke and flames we see are evidence that fire has mass and occupies space.
So, while fire isn't a substance in itself, it's a process involving the transformation of matter.
