1. Do now! Can you continue the questions on pages 84 and 85?

2. Last lesson Chemical and physical weathering

3. Chemical weathering Rain is slightly acidic as it contains substances dissolved from the air. It can react with rock, dissolving it.

4. Chemical weathering Some rocks are dissolved more by acid rain than others Limestone “pavement”

5. Physical weathering Rocks can be weathered by physical changes

6. Physical weathering When rocks are hot they expand, and when they cool they contract. Repeated changes cause the rock to crack, often causing rock to peel off. Sometimes called “onion-skin weathering”

7. Physical weathering Freeze-thaw weathering is another example You now know all about freeze-thaw weathering

8. Today’s lesson Transport of weathered rock Soil Rock cycle

9. Transport

10. Rock falls to the bottom of rock faces and may be transported away by fast moving streams.

11. Abrasion The rocks in the stream bed rub against each other and wear away. This is abrasion.

12. Sediment The bits of rock in the stream bed are called sediment.

13. Deposit Smaller rock fragments are carried further than large ones, eventually being deposited on the bottom in slow water.

14. Let’s try some questions! Stick the sheet in and fill in the gaps. You have 8 minutes!

15. What is soil?

16. A mixture of stones, smaller rock particles (sand) and humus (remains of dead plants and animals)

17. Copy?! Can you copy the table on page 91?

18. The Rock Cycle Can you read page 100 very carefully?

19. The Rock Cycle Can you copy the diagram on page 100?