Matter can exist as solid, liquid, gas, and it can change from one state to another. These changes happen when we add or remove energy, usually in the form of heat. These processes are called phase changes or state transitions, and they occur because particles move faster when heated and slower when cooled.

Let’s break it down step by step!

1. Melting (Solid → Liquid)

• What Happens: When you heat a solid, its particles start vibrating faster. If enough heat is added, the particles break free from their fixed positions and move more freely.

• Example: Ice melting into water. You add heat, and the ice turns into liquid water.

2. Freezing (Liquid → Solid)

• What Happens: When you remove heat from a liquid, its particles slow down. Eventually, they lock into fixed positions and form a solid.

• Example: Water freezing into ice. Take away heat, and water turns solid in your freezer.

3. Evaporation (Liquid → Gas)

• What Happens: When you heat a liquid, its particles gain enough energy to escape into the air as a gas. This happens at the surface of the liquid.

• Example: A puddle of water drying up on a sunny day. The heat from the sun turns the water into water vapor.

5. Condensation (Gas → Liquid)

• What Happens: When you cool a gas, its particles lose energy and come closer together, turning into a liquid.

• Example: Steam from hot tea turning into water droplets on a cold lid.

6. Sublimation (Solid → Gas)

• What Happens: Some solids can skip the liquid phase and turn directly into a gas when heated.

• Example: Dry ice (frozen carbon dioxide) turning into fog-like gas.

7. Deposition (Gas → Solid)

• What Happens: A gas can turn directly into a solid when it loses heat quickly.

• Example: Frost forming on a cold window. The water vapor in the air turns into ice without becoming liquid first.

Key Idea

• Adding Heat: Makes particles move faster. Solid → Liquid → Gas .

• Removing Heat: Makes particles slow down. Gas → Liquid → Solid.

Everyday Examples

• Melting: Ice cream melting on a hot day.

• Freezing: Water turning into ice in your freezer.

• Evaporation: Clothes drying in the sun.

• Condensation: Dew forming on grass in the morning.

• Sublimation: Dry ice turning into gas.

• Deposition: Frost forming on windows.

These changes in states of matter happen all around us every day and are part of important natural processes, like the water cycle! 🌡️💧