Chemical Change:
* Chemical Reaction
* Chemical Transformation
* Irreversible Change
* New Substance Formation
* Composition Change
* Permanent Change
Physical Change:
* Physical Transformation
* Reversible Change
* Appearance Change
* State Change
* Phase Change
* Temporary Change
Examples:
Chemical Change:
* Burning wood: Wood combines with oxygen to form ash, carbon dioxide, and water, all new substances.
* Cooking an egg: The protein in the egg changes its structure due to heat, creating a new substance.
* Rusting of iron: Iron reacts with oxygen and water to form iron oxide, a new substance.
Physical Change:
* Melting ice: Water changes its state from solid to liquid, but its chemical composition remains the same (H₂O).
* Boiling water: Water changes its state from liquid to gas, but its chemical composition remains the same (H₂O).
* Crushing a can: The can changes its shape, but its chemical composition remains the same.
* Dissolving sugar in water: Sugar disperses in the water, but its chemical composition remains the same. It can be recovered by evaporating the water.
Key Takeaway:
The key difference between a chemical change and a physical change is whether a new substance is formed. If a new substance is formed, it's a chemical change. If the substance remains the same, even if its appearance or state changes, it's a physical change.
