1. ____- hard and rigid, the Earth's outermost and _____ layer. Only a few miles (5 km) thick under the oceans and averaging 20 miles thick under the continents.
2. ________- Divided into two sub regions, upper and lower, this dense layer made of hot semi rock is located directly below ____ and is about 1800 miles thick.
3. ______ ____- The only _____ layer of the Earth- a sea of mostly iron and nickel. It is roughly 1800- 3200 miles below the surface and about 1400 miles thick. Temparatures reach ____°C.
4. _______ _____- An extremely hot, solid sphere of mostly _____ and ______ at the center of the Earth. It is 3200 to 3960 miles below the surface and about 750 miles in diameter.
5. How do you think scientists discovered the layers of our Earth?
5.) scientist discovered the layers of our Earth with experts like Geologist and Paleontologist who study the earth's structure, origin and composition.
