Puzzling Earth

5. The rigid, outermost layer of the Earth's rocks and minerals, which consists of the crust and upper mantle.
6. (Dating):A method used to date rocks and other objects based on the known decay rate of radioactive isotopes.
9. 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.
11. (Current):Heat-driven cycles that occur in the air, ocean, and mantle.
12. the region of the earth's atmosphere above the stratosphere and below the thermosphere, between about 30 and 50 miles (50 and 80 km) in altitude.
13. (Core): This core is incredibly dense and composed primarily of iron and nickel.
15. (Core): Liquid, iron-nickel layer of the Earth and is also responsible for the magnetic field.
16. A neutrino or antineutrino emitted in decay of radionuclide naturally occurring in the Earth.
17. (Isotope):The resulting chemical nuclide that is left after the original isotope decays.
19. The mantle is a layer within the Earth between the crust and the core.
20. (Boundary):When two tectonic plates move away from each other. Along these boundaries, earthquakes and magma are common.

1. (Decay): The process in which a radioactive atom spontaneously gives off radiation in the form of energy or particles to reach a more stable state.
2. (Isotope):The isotope that decays, forming the daughter isotope after releasing a decay particle.
3. (Tectonics):a theory explaining the structure of the earth's crust and many associated phenomena as resulting from the interaction of rigid lithospheric plates which move slowly over the underlying mantle.
4. (Boundary):An area on Earth where two or more lithospheric plates collide.
7. (crust): Plates that are located beneath the ocean
8. A solid piece of debris from an object, such as a comet, asteroid
10. (Boundary):Places where plates slide sideways past each other.
14. (crust): The layer of granitic, sedimentary, and metamorphic rocks, which form the continents.
18. (wave):A mechanical wave of acoustic energy that travels through the Earth or another planetary body.