Changing state
Changing states means a substance can change its form when heat is added or removed.Its particles move differently in each state, so when temperature changes, the state also changes.
When Heat Is Added
Melting — Solid → LiquidHeat makes particles move faster and loosen up.Example: Ice becomes water.
Evaporation — boiling - Liquid → Gas/ Boiling More heat makes particles spread far apart.Example: Water becomes steam.
When Heat Is Removed
Freezing — Liquid → SolidCooling slows particles and locks them in place.Example: Water becomes ice.
Condensation —Cooling makes particles come closer again.Example: Steam becomes water droplets.
Extra changes (special cases)
Sublimation — Solid → Gas Some solids skip the liquid stage.Example: Camphor, dry ice.
Deposition — Gas → Solid Gas becomes solid directly.Example: Frost forming on leaves.
Fun Fact
When water changes from liquid to gas and back again, it’s the same water that dinosaurs drank millions of years ago!
So the water you drink today might have been part of a cloud, an ocean, or even dinosaur spit long, long ago!





