Across
- 2. nucleus of an unstable atom loses energy by emitting radiation
- 3. structures of the Earth's crust and results of the rigid plates that move over the mantels
- 5. process by which rock is broken down such as erosion or weathering
- 10. a tectonic boundary where two plates move toward each other
- 11. study of earthquakes
- 15. time taken for the isotope to decrease into half its original value
- 16. study of the magnetism in rocks
- 17. different forms of the same element that have a different number of neutrons
- 18. tectonic plates meet and the edge of one plate descends below the edge of the other
- 19. true age of a rock or fossil
- 20. representation of a map of natural and artificial features of an area
- 21. dating rocks using relative proportions of particular radioactive isotopes
Down
- 1. where two plates slide against each other in a sideways motion
- 4. movement in a fluid where hotter and less dense matter rises and cooler and less matter sinks
- 6. forms the nuclear mass of a continent or the central basin of an ocean
- 7. determining the relative order of events or objects (past)
- 8. meteor that survives its passage through Earth's atmosphere and hits the ground
- 9. a tectonic plate boundary where two plates are moving away from each other
- 12. massive irregularly shaped slab of solid rock; tectonic plate
- 13. processes that help build Earth up
- 14. waves of energy that travel through the earth's layers