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7th grade · Science · Unit 7 of 8

Earth's Moving Surface

Plates, the rock cycle and the Cascades.

What your child practices

Practices plate tectonics and evidence from fossils, rocks and continent shapes, the rock cycle, and how processes at different speeds shape Earth's surface, including the Cascade volcanoes.

Arizona Academic Standards learning standard: 7.E1U1.6; 7.E1U1.5 · evidence of moving plates in rocks, fossils and continents, and the cycling of matter on Earth

How we explain it

Children can open this short lesson before they practice.

  1. Matching coastlines, fossils and rocks on far-apart continents show they were once joined.
  2. Plates pull apart at mid-ocean ridges and collide to build mountains and volcanoes, such as the Cascades.
  3. Some changes are sudden (earthquakes); others take millions of years (mountain building).

Example: Is a landslide a fast or a very slow change to Earth’s surface? A landslide happens in minutes. Mountain building takes millions of years. Answer: fast

Earth's Moving Surface in Arizona

In the Arizona Academic Standards, this is unit 7 of 8 in 7th grade Science, after Electromagnets & Generators and before Weather and the Water Cycle.

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.

Source: Arizona Department of Education

Sample questions

A taste of this unit. In the app, questions change every time and get easier or harder to match your child.

  1. Question 1

    Rock formed from layers of pressed sediment is…

    • sedimentary
    • metamorphic
    • volcanic
    • igneous

  2. Question 2

    Weathering and erosion turn rock into…

    • metamorphic rock
    • magma
    • lava
    • sediment

  3. Question 3

    The Cascade volcanoes formed because…

    • glaciers built them
    • a meteor hit
    • plates pull apart in the middle of a continent
    • one plate sinks under another

  4. Question 4

    Rock formed from cooled magma or lava is…

    • fossil
    • sedimentary
    • metamorphic
    • igneous

  5. Question 5

    What drives plate motion?

    • Heat from inside Earth
    • Wind
    • Ocean waves
    • The moon's light

  6. Question 6

    Why does the rock cycle have no beginning or end?

    • Rocks never change
    • Any rock type can change into another
    • Only igneous rocks change
    • Rocks disappear

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