Chemical changes are changes in the molecular structure of a substance. Usually in a Chemical Change, a new substance is formed. There are a few indicators that tell you that a chemical change has happened:
- Gas is produced (bubbles seen)
- Light is produced
- Change in color
- Change is temperature
- Precipitate formed (leftover substance)
Look for these pointers when you are deciding if a chemical change has happened. There is actually a way to remember if a Chemical Change has occurred.
Cooking is a chemical change because the object actually changes. When you roast, heat, or cook something, the molecular compounds or makeup of the food changes. When you bake a cake, it changes color, produces gas through fermentation, and is a change in temperature. It is not reversible.