Lesson 7 of 9
The big picture
Show on a big screenIce, water and vapour are one water. Heat moves the water between forms.
| Idea | Remember |
|---|---|
| Three forms, one water | Freezes at 0 °C, boils at 100 °C. Vapour is invisible. |
| Evaporation | Liquid to vapour at almost any temperature. Faster with surface, warmth and wind. |
| Condensation | Vapour to liquid on a cold surface. Drops come from the air. |
| Melting and freezing | Opposite changes. Water is never used up. |
| The water cycle | Evaporation, condensation, rain, flowing back. The Sun drives it. |
| Cooling by evaporation | Evaporating water takes warmth away. |
Now open Chapter 8 in your NCERT book. You have tried every idea.