* Physical Changes: Alter the form or appearance of a substance but don't change its chemical composition. Examples include:
* Dissolving sugar in water
* Melting ice
* Boiling water
* Crushing a rock
* Chemical Changes: Result in the formation of new substances with different chemical properties. Examples include:
* Burning wood
* Baking a cake
* Rusting iron
Why adding drink powder to water is a physical change:
* No new substances are formed. The drink powder simply dissolves in the water. The water molecules separate the powder particles, but the individual components of the powder (sugars, flavors, etc.) remain unchanged.
* The change is reversible. You can recover the drink powder by evaporating the water.
Key takeaway: Dissolving is a physical change because it involves a change in state (from solid powder to dissolved particles) but not a change in the chemical makeup of the ingredients.
