1. Chapter 3 Section 1
The Earth System

2. Crust: the thin and solid outermost layer of Earth above the mantle.
Mantle: the layer of rock between Earth’s crust and core.
Core: the central part of Earth below the mantle.

3. Convection: the movement of matter due to differences in density; the transfer of energy due to the movement of matter.
Convection current: any movement of matter that results from differences in density; may be vertical, circular, or cyclical.

4. Asthenosphere: the physical layer of Earth upon which tectonic plates move.
Lithosphere: the physical layer of Earth that is divided into tectonic plates.

5. Atmosphere: a mixture of gases surrounding Earth.
Mesosphere: the physical layer of Earth that is the lower, solid layer of the mantle.
Outer core: the physical layer of Earth that is made of liquid iron and nickel.