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7th grade · Science · Unit 8 of 10

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.

Alaska content standards learning standard: MS-ESS2-1; MS-ESS2-2; MS-ESS2-3 · the rock cycle, surface processes at different scales, and evidence for plate motion

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 Alaska

In the Alaska content standards, this is unit 8 of 10 in 7th grade Science, after Chemical Reactions and before Mixtures & Solutions.

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: Alaska Department of Education and Early Development

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

    Which process is very fast?

    • Canyon formation
    • An earthquake
    • Erosion of a mountain range
    • Plates drifting

  2. Question 2

    Mid-ocean ridges are where plates…

    • crash together
    • pull apart and new crust forms
    • slide under
    • stop moving

  3. Question 3

    Rock formed from layers of pressed sediment is…

    • metamorphic
    • sedimentary
    • igneous
    • volcanic

  4. Question 4

    Earth's outer layer is broken into large pieces called…

    • tectonic plates
    • crusts of ice
    • mantle cells
    • cores

  5. Question 5

    Rock changed by heat and pressure is…

    • sedimentary
    • volcanic glass
    • metamorphic
    • igneous

  6. Question 6

    The Himalayas are still rising because…

    • glaciers are adding ice
    • two continental plates are colliding
    • lava flows there
    • rain builds them

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