Water moves in a never-ending loop called the water cycle. The Sun warms water so it evaporates into the air, the water vapour cools and condenses into clouds, and it falls back down as rain, snow or hail.
Apa yang akan dipelajari anak anda
- Know that water can be a solid (ice), a liquid and a gas (water vapour)
- Describe evaporation and condensation
- Describe the water cycle in order
- Know that water freezes at 0°C and boils at 100°C
Round and round
Puddles dry up because the water evaporates. On a cold window, water vapour from the air cools and condenses into droplets. The same thing happens high in the sky, making clouds. When the drops get heavy, they fall as rain and flow back to rivers and the sea — and the cycle starts again.
Contoh soalan
Berikut ialah beberapa soalan seperti dalam misi pertama. Bolehkah anda menjawabnya?
1. What is ice?
- Salt
- Frozen water
- Glass
- Hot water
Tunjuk jawapan
Jawapan: Frozen water. Ice is water that has frozen solid.
2. Where does rain come from?
- The ground
- Clouds
- Trees
- The Sun
Tunjuk jawapan
Jawapan: Clouds. Rain falls from clouds.
3. Which of these is a liquid?
- A stone
- Water
- Ice
- A spoon
Tunjuk jawapan
Jawapan: Water. Water flows and can be poured.
Tip untuk orang dewasa
- Draw around a puddle with chalk and check it every hour.
- Breathe on a cold mirror and watch condensation appear.
- Hang washing out on a warm, windy day and a cold, still day. Which dries faster?