3. Oxygen is the most abundant element in the Earth’s crust.

4.  The elements silicon, oxygen, iron and magnesium make up the mantle.

5. The upper mantle has with it a soft weak layer called the asthenosphere, which is capable of flowing. This property facilitates the movement of the lithospheric plates.

6. The scientists were able to show that the outer core is liquid due to the fact that S- waves cannot travel through this Earth’s layer as proven by the S-wave shadow zone.

7. The inner core is mostly made up of iron and nickel.

8. The inner core is solid. This is due to the very high pressure that keeps it compacted together even if the temperature is really very high.

9. The outer and the inner core are made mostly of iron and nickel. The outer core reaches a temperature of 2000oC. With this temperature, the iron and nickel melt thus, this layer is liquid. The inner core has a temperature as high as 5000oC. It is compact despite of the very hot temperature because of the very great pressure that keeps this layer in the solid phase.
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