chapter 2

Question 0

melted iron and nickel; 1,800 miles below surface

Answer 0

outer core

Question 1

solid; nickel and iron; 4,000 miles below the surface

Answer 1

inner core

Question 2

hot rock; silicon, oxygen, aluminum, iron magnesium

Answer 2

mantle

Question 3

3 to 30 miles deep; plates float on upper mantle

Answer 3

crust

Question 4

the theory that the continents were once joined and slowly ripped apart

Answer 4

continental drift

Question 5

one super-continent that existed millions of years ago

Answer 5

Pangea

Question 6

internal forces cause the earth’s plates to move about ___ inches a year

Answer 6

4

Question 7

when one plate collides with another and the heavier plate slides under the lighter plate

Answer 7

subduction

Question 8

bends in layers of rock

Answer 8

folds

Question 9

breaks in the earth’s surface

Answer 9

faults

Question 10

____ often occur where different plates meet each other

Answer 10

earthquakes

Question 11

where most earthquakes and volcanoes occur

Answer 11

ring of fire

Question 12

mountains formed when lava rises through the earth’s crust

Answer 12

volcanoes

Question 13

tidal wave caused by underwater earthquakes

Answer 13

tsunamis

Question 14

process that breaks rocks into pieces

Answer 14

weathering

Question 15

water dissolves some chemicals in rocks causing them to crumble

Answer 15

chemical weathering

Question 16

water seeps into cracks of rocks, it freezes and expands, forcing it apart

Answer 16

physical weathering

Question 17

moves dust, sand, and soil; results in sand dunes

Answer 17

wind erosion

Question 18

flowing water cuts into the land; results in valleys and canyons

Answer 18

water erosion

Question 19

land is changed as large bodies of ice move across it, creating lakes and valleys

Answer 19

glacier erosion

Question 20

ice that covers large areas (ice caps)

Answer 20

sheet glaciers

Question 21

when fallen snow in mountain builds up and turns to ice

Answer 21

mountain glacier

Question 22

regular movement of water from the ocean to air to ground and back to the ocean

Answer 22

water cycle

Question 23

suns heat causes vapor from oceans to rise to form clouds

Answer 23

evaporation

Question 24

when warm air cools and water vapor turns to liquid water

Answer 24

condensation