1. How much of the Earth is covered with water?
👉 About 71%
2. What is the main source of water on Earth?
👉 Oceans
3. What percentage of water is saline?
👉 About 97%
4. What percentage of water is freshwater?
👉 About 3%
5. Where is most freshwater found?
👉 Glaciers and ice caps
6. Name two sources of freshwater.
👉 Rivers, lakes
7. What is the water cycle?
👉 Continuous water movement
8. Name the first stage of water cycle.
👉 Evaporation
9. What is evaporation?
👉 Water changing to vapour
10. What is condensation?
👉 Vapour to water
11. What is precipitation?
👉 Falling of water
12. Name one form of precipitation.
👉 Rain
13. What is transpiration?
👉 Water loss from plants
14. What are ocean waters called?
👉 Saline water
15. Why is ocean water salty?
👉 Dissolved salts
16. Name the three major oceans.
👉 Pacific, Atlantic, Indian
17. What are waves?
👉 Rising and falling water
18. What causes waves?
👉 Wind
19. What are tides?
👉 Rise and fall of sea
20. What causes tides?
👉 Gravitational pull
21. Which heavenly bodies cause tides?
👉 Moon and Sun
22. What are ocean currents?
👉 Flowing ocean water
23. Name one warm ocean current.
👉 Gulf Stream
24. Name one cold ocean current.
👉 Labrador Current
25. What is groundwater?
👉 Water below surface
26. How is groundwater recharged?
👉 Rainwater seepage
27. What is water scarcity?
👉 Shortage of water
28. Name one cause of water scarcity.
👉 Overuse
29. How can we conserve water?
👉 Save and reuse
30. Why is water important?
👉 Supports life
📌 Quick Revision Tricks
👉 Water Cycle:
E-C-P → Evaporation – Condensation – Precipitation
👉 Ocean Movements:
W-T-C → Waves – Tides – Currents