6th grade · Science · Unit 9 of 10
Earth's Changing Surface
How plate movement, weathering and erosion shape Earth's surface.
What your child practices
Your child explains how moving plates build mountains and how weathering and erosion wear them down over time.
Alabama Course of Study content standard: 6.5; 6.6 · how plate movement, weathering and erosion shape Earth's surface
How we explain it
Children can open this short lesson before they practice.
- Plates move: earthquakes are common where plates slide past each other.
- New crust forms at ocean ridges and moves outward, so seafloor rock is youngest near ridges.
- Igneous rock, like granite, forms from cooled magma or lava.
- Glaciers, water and wind slowly carve the land over thousands of years.
Example: Seafloor rock is youngest near a ridge and older farther away. What does this show? New rock forms at the ridge. Then it slowly moves outward. Answer: new crust forms at ridges and moves outward
Earth's Changing Surface in Alabama
In the Alabama Course of Study, this is unit 9 of 10 in 6th grade Science, after Climate & Climate Change and before Earth's History & Fossils.
Gradelings describes a child's practice on this unit as Beginning, Approaching, Meeting or Exceeding (Four practice steps). That reflects practice, not a report-card mark: the teacher decides the mark.
Sample questions
A taste of this unit. In the app, questions change every time and get easier or harder to match your child.
Question 1
Earth's outer layer is broken into large pieces called…
- crusts of ice
- tectonic plates
- cores
- mantle cells
tectonic plates
Hint: They move slowly.
Question 2
Rock formed from layers of pressed sediment is…
- volcanic
- metamorphic
- sedimentary
- igneous
sedimentary
Hint: Layers.
Question 3
Over millions of years, rain and rivers have made old mountains like the Appalachians…
- hotter
- lower and rounder
- taller and sharper
- younger
lower and rounder
Hint: Weathering and erosion wear land down.
Question 4
Why does the rock cycle have no beginning or end?
- Rocks never change
- Any rock type can change into another
- Rocks disappear
- Only igneous rocks change
Any rock type can change into another
Hint: It's a cycle.
Question 5
Sediment carried by the Hudson River settles out where the river…
- freezes in winter
- slows down as it meets the ocean
- flows uphill
- speeds up over rapids
slows down as it meets the ocean
Hint: Slower water drops sediment.
Question 6
Matching fossils on continents now far apart are evidence that…
- they formed recently
- birds carried them
- fossils swim
- the continents were once joined
the continents were once joined
Hint: Pangaea.