Chemical Change When does Chemical Change Occur? What happens when Chemical Change Occurs?

Chemical Changes Chemical Changes occur when elements combine and/or react with each other. This interaction can cause elements to change their physical and/or chemical properties. Most of the time, these changes are permanent and are difficult to reverse.

Example: When you burn a candle: The oxygen in the air is allowing it to burn (gas) The flame is producing heat and supplying light. The flame is using up the candles’ energy to fuel itself, therefore the candle disappears. THESE ARE EXAMPLES OF CHEMICAL CHANGES

Some common indicators of chemical change are: Bubbles of gas Heat loss or gain Light emission Colour changes

Some common indicators of chemical change are: Solid material called a ‘precipitate’ forms in a liquid Production of a new substance PRECIPITATE 

Demos of Chemical Change Vinegar and Baking Soda – What is the chemical change? Mentos and Diet Coke – What is the chemical change? Elephant’s Toothpaste – What is the chemical change?