chapter 7

8. all the continents were a part of one supper continent
9. the denser plate sinks below the more buoyant plate
11. tectonics earth surface is made of rigid rock or plates that move with respect to each other
12. plate boundaries where two plates collide
13. polarity magnetized objects will orient themselves to point south
16. polarity magnetized objects such as compass needles will orient themselves to point north

1. the cold rigid and outermost layer
2. plate boundary forms when two plates separate
3. drift continents are in constant motion
4. spreading is the process by which new oceanic crusts form along a mid-ocean ridge and older oceanic crust moves away from the ridge
5. the circulation of material caused by differences in temperature and density
6. reversal the magnetic field reverses direction
7. ridges mountain ranges in the middle of the ocean
10. push moves lithosphere in opposite directions away from the mid-ocean ridge
14. plate boundary forms where two plates pass each other
15. pull as a slab sinks it pulls the rest of the plate down