1. crust the metallic layer at the earth's center 2. inner core the layer surrounding the inner core 3. lower mantle the firm layer between the crust and the asthenosphere 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 semi-solid layer between the top layer and the upper mantle