Structure of the Earth

1. The inner core is composed of an iron-nickel ____________.
3. Continental crust is mostly composed of this substance.
4. The outer core is composed of ________ and nickel.
8. The lithosphere is broken into ___________ ____________.
11. The lithosphere can be described as hard and ___________.
12. Number of layers found in Earth.
13. The layer of Earth composed of the asthenosphere and mesosphere.
14. The mesosphere has a higher pressure than the asthenosphere, making it ______ and more rigid.
16. The layer found underneath the mantle.
18. The asthenosphere exhibits ____________ properties; that is, it can move
19. The inner core has a _______ of approximately 1200km.
20. Oceanic crust is mostly composed of this substance.
21. Crust contains elements such as silicon, aluminium, ___________ and potassium.

2. The layer of Earth composed of the crust and uppermost mantle.
5. The innermost layer of Earth.
6. Currents in the iron nickel fluid of the outer core influence Earth's __________ __________.
7. The inner core is a ________ ball.
8. The crust is the thinnest layer of Earth, the mantle is the _______________.
9. The thick type of crust that forms the continents.
10. The mantle contains __________ _________ which are rich in iron and magnesium.
15. The outer core is a __________ layer.
17. The thin type of crust found under oceans and seas.