* Change in Appearance:
* Color Change: The wood turns black (ash) and the flames are a different color than the wood itself.
* Physical State Change: Solid wood transforms into ash (solid) and smoke (gases).
* Release of Energy:
* Heat: The wood gets hot and releases a significant amount of heat.
* Light: Flames produce visible light.
* Production of New Substances:
* Ash: The ash is a new substance with different chemical properties than the original wood.
* Smoke: Smoke consists of gases and particles that weren't present in the original wood.
* Carbon Dioxide: Burning wood releases carbon dioxide gas, which wasn't present in the wood before.
Explanation:
Burning wood is a combustion reaction. It involves a chemical change where the wood reacts with oxygen in the air. The reactants (wood and oxygen) are transformed into different products (ash, smoke, gases like carbon dioxide and water vapor). This transformation is accompanied by a release of energy (heat and light).
Key Idea: A chemical reaction always involves the formation of new substances with different properties from the original reactants. The changes in appearance, energy release, and the production of new substances are all clear indicators of a chemical reaction.
