Water - Rain

1. Rain is important for life as all living things need water to live.

2. Oceans are the main source of rain, but lakes and rivers also contribute.

3. The heat from the sun warms the surface of the water in puddles, streams and oceans.

4. The particles of water change from a liquid to a gas, called water vapour, and rise upwards.

5. As the water vapour rises in the atmosphere, it cools and turns back into tiny particles of liquid.

6. As the droplets get bigger, they stick together and make clouds.

7. The droplets of water become larger and heavier as more droplets stick together.

8. As the droplets become too heavy to be held in the air, they fall to the earth as rain.

9. Formation of rain clouds can be very local - there may only be one in the area and the rest of the sky may be sunny.

10. Many people think that raindrops are tear-shaped, but only drops of water dripping from something are this shape.

11. Most raindrops are spherical, like a ball.

12. Their shape changes as they fall to the ground due to the speed at which they travel.

13. This flattens the bottom of the raindrop and creates a curved dome on the top.

14. In a thunderstorm raindrops may become large and fall as hail.

15. When temperatures are below freezing all the way to the ground, the droplets fall as snow.

16. Meteorologists classify rain according to its rate of fall - light, moderate and heavy.

17. The presence of mountains can influence the amount of rain that falls locally.

18. The highest rainfall totals occur near the Equator in the tropics.

19. The lowest rainfall is at the Polar regions because the air is too cold.

20. Some parts of the Arctic and Antarctic are as dry as the desert.

21. Temperate regions like the British Isles receive regular rainfall and are neither too wet nor too dry.

22. Long periods of heavy rain can lead to floods when the land becomes saturated and the water flows into the rivers.

23. The extra water rushes downstream, where the water flows more slowly, and the river breaks its banks.

24. Droughts happen when there is not enough rainfall and cause crops to fail and animals to die.

25. When light from the sun strikes a collection of water drops, a rainbow may appear.

26. It appears as a multi-coloured arc whose ends appear to touch the Earth.

27. Rainbows appear in the part of the sky opposite the sun.

28. They are frequently seen in the early morning, or the late afternoon when the sun is low.

29. The colours of the rainbow are red, orange, yellow, green, blue, indigo and violet.

30. Occasionally, a secondary bow may be seen which is less intense than the primary one and has its colours reversed.