Match each term to its description. 1. crust
the semi-solid layer between the top layer and the upper mantle
2. inner core
the metallic layer at the earth's center
3. lower mantle
the layer surrounding the inner core
4. asthenosphere
the layer between the asthenosphere and lower mantle
5. upper mantle
the earth's outermost layer
6. top layer
the hottest part of the mantle
7. outer core
the firm layer between the crust and the asthenosphere