Grade 5 Science Matter – Change Of State Notes
Science — Matter
Subtopic: Change of State (for age 10)
Matter is anything that takes up space. Matter can be a solid, a liquid or a gas. A change of state happens when matter changes from one of these forms to another because of heating or cooling.
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Solid
Particles packed tightly. Keeps its shape (e.g., rock, ice).
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Liquid
Particles move around but stay close. Takes the shape of its container (e.g., water, milk).
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Gas
Particles are far apart and move fast. No fixed shape (e.g., air, steam).
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Common changes of state
- Melting — solid → liquid (ice melts to water). Example: ice cubes in a soda or on a hot roof.
- Freezing — liquid → solid (water freezes to ice). Example: making ice cubes in a freezer.
- Evaporation — liquid → gas (water on the ground dries up). Example: puddles disappear after the sun comes out; clothes drying on a line.
- Condensation — gas → liquid (water forms on a cold glass or dew on grass). Example: morning dew on tea farms or water drops on a cold soda can.
- Sublimation — solid → gas (rare at home; some mothballs slowly go from solid to gas).
- Deposition — gas → solid (gas becomes solid without becoming liquid first; frost forms on very cold surfaces).
Why does it happen?
Heating gives particles more energy so they move faster and can change from solid to liquid or liquid to gas. Cooling takes energy away so particles slow down and may change from gas to liquid or liquid to solid.
Everyday Kenyan examples
- Water from a jiko boiling to make tea → steam (evaporation).
- Morning dew on grass in tea and flower farms → condensation.
- Clothes drying on a line in the sun → evaporation helps them dry.
- Ice cream melting under the hot sun → melting.
Simple activities (safe, do with an adult when needed)
- Ice-on-a-plate: Put an ice cube on a plate in the sun. Observe how it changes to water. Ask: How long did it take? What is happening?
- Puddle watch: After rain, mark a small puddle and check every hour. Watch it get smaller because of evaporation.
- Foggy mirror (bathroom): After a warm shower, look at the mirror—tiny drops of water form (condensation). Wipe a path and watch the clear space return as more water condenses.
Safety first
Always ask an adult to help when using hot water, stoves or freezers.
Key words to learn
melting point, boiling point, evaporation, condensation, freeze, heat, cool
Short questions (try these)
- What change of state happens when ice becomes water?
- Why do clothes dry when left in the sun?
- Give one example of condensation you have seen in your home or school.
Remember:
Heating usually turns solids → liquids → gases. Cooling usually turns gases → liquids → solids.