Science

4. fluid's internal resistance to flow or deformation, acting as a measure of its "thickness" or friction
5. super-hot, dense center, made mostly of iron and nickel, and divided into a liquid outer core and a solid inner core
6. solid, extremely hot, and dense sphere of iron-nickel alloy, located about 5,150 km below the surface
8. vibrations of energy caused by the sudden breaking of rock in the Earth's crust (earthquakes), volcanic eruptions, or explosions, propagating through the Earth's interior and along its surface
9. rigid, outermost rocky shell of Earth, comprising the crust and uppermost mantle, with a thickness of roughly \(100\text{--}200\) km. It is divided into tectonic plates that move over the plastic-like asthenosphere

1. ~2,200–2,300 km thick,, liquid layer composed primarily of iron and nickel, situated between the solid inner core and the mantle at depths of roughly 2,900 to 5,150 km
2. 2,900-kilometer (1,800-mile) thick layer of solid silicate rock, rich in magnesium and iron, that makes up 84% of Earth's volume
3. the upper layer of the earth's mantle, below the lithosphere, in which there is relatively low resistance to plastic flow and convection is thought to occur
7. measurement of how much mass is packed into a given volume, calculated by dividing an object's mass by its volume