Physical and Chemical Changes
Understanding Matter Transformations
Explore the difference between physical changes (reversible) and chemical changes (irreversible). Try melting ice, boiling water, and creating chemical reactions to observe how matter transforms!
Observation:
Start by adding ice or baking soda to the beaker to begin experiments.
The Science Behind Physical and Chemical Changes
Physical Changes:
Physical changes affect the form of matter but not its chemical composition:
- Reversible: Can return to original state
- Examples: Melting ice, boiling water, dissolving salt
- No new substances formed: Water molecules remain H₂O
Chemical Changes:
Chemical changes create new substances with different properties:
- Irreversible: Cannot easily return to original substances
- Examples: Burning wood, rusting iron, baking cake
- New substances formed: Atoms rearrange into new molecules
Identifying Changes:
Signs of chemical changes include:
- Color change
- Gas production (bubbles)
- Temperature change
- Formation of precipitate
- Odor change
