How does freezing water cause the weathering of rocks?  The freezing water—

• keeps the rocks in place
• makes the rocks last longer
• expands cracks and breaks rocks
• causes rocks to fall in landslides

What is this landform?

• valley
• hills
• river
• lake

Which of the following is an example of chemical weathering?

• Acid rain dissolving limestone
• roots breaking into concrete
• paper being ripped
• Water running over rocks

A cliff formed near the ocean.  Which statement best describes how this cliff formed?

• Warm air melted the rock.
• Sun rays evaporated the rock.
• Ocean waves washed away rock.
• Plant roots pushed away the rock.

Acid rain is an example of chemical weathering because

• pollution is in the sky
• rain connected to dust falls and hits rocks so hard they break.
• there is friction between rain and rocks.
• pollution gets dissolved in water and falls as rain dissolving rocks over time.

How do plants weather rocks?

• during photosynthesis
• when roots grow into cracks of rocks and expand the rock
• when the plant moves water from the roots to the leaves
• Plants don't weather rocks

What is this landform?

• mountain
• canyon
• coast
• cliff

What is mechanical weathering?

• Process through which rocks are physically broken into smaller pieces.
• Rocks are broken down through chemical changes.
• Rocks are worn away from acid in plant roots.
• Rocks broken down by machinery.

Sand dunes like the ones pictured above are most likely caused by —

• rain
• glaciers
• wind
• water

The process that breaks down rocks and other materials on Earth's surface is called

• Weathering
• Erosion
• Deposition
• Decomposition