1. 1

2. 1.The Structure of Earth 2

3. Earth is shaped like a ball and is made up of four layers. 3 It is about 8,000 miles in diameter

4. Layers of Earth 4 At the very center of Earth is the inner core

5. 5 Vocabulary Inner core The center of Earth that is about 800 miles thick and made of solid iron and nickel

6. Although it is hot enough to melt, the inner core is solid because it is under so much pressure from the layers above 6 The inner core is very hot, about 9,000 0 F

7. 7 The molecules of iron and nickel cannot spread out enough to become liquid IronNickel

8. 8 Iron and nickel causing magnetic fields (blue are movements inward and yellow are movements outward)

9. 9 The outer core is about 1,400 miles thick Vocabulary: Outer core The layer of Earth is outside the inner core and made of hot liquid metal

10. The temperature of the outer core ranges from 4,000 0 F to 9,000 0 F 10

11. 11 Because the outer core is not under as much pressure as the inner core, the iron and nickel have melted (molten)

12. The outer core is made of hot liquid metal 12

13. The mantle is the 3 rd layer of the Earth 13 Vocabulary: mantle The thickest layer of Earth that lies just below the crust

14. 14 The mantle seems to be made up of several layers

15. The top layer of the mantle is hot solid rock 15 The bottom layer is liquid rock

16. The rocks in the mantle are made mostly of silicon, aluminum, iron, and magnesium 16

17. 17 The crust is the 4th layer of Earth Vocabulary: crust The outer layer of Earth that makes up the continents and ocean floors

18. 18 The crust is about 20 miles thick in most places But can be as little as 5 miles thick

19. 19 The crust makes up the continents and ocean floors

20. 20 The crust is made up of many kinds of rock, such as granite, sandstone, and marble

21. 21