| A | B |
|---|
| mantle | A layer directly beneath the Earth's crust |
| crust | the Earth's outermost layer |
| core | the Earth's innermost layer |
| asthenosphere | a zone of partly melted rock inthe upper mantle |
| lithosphere | cool, solid portion that involves the crust and upper mantle |
| inner core | solid, made mostly of iron and nickel |
| outer core | liquid, made mostly of iron and nickel |
| plasticity | a property that allows an object to float |
| plate tectonics | a theory scientists use to explain plate movements |
| tectonics | from the Greek word meaning, "builder" |
