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7th grade · Science · Unit 18 of 18

Plate Tectonics

Evidence that Earth has changed, and how moving plates build mountains, basins and volcanoes.

What your child practices

Practices the evidence that Earth has changed over time (fossils, matching continents, superposition of rock layers) and how plate tectonics causes ocean basins, earthquakes, mountain building and volcanic eruptions, including hot spots and supervolcanoes such as Yellowstone.

Texas Essential Knowledge and Skills (TEKS) teks student expectation: 7.10(A); 7.10(B) · evidence that Earth has changed, and how plate tectonics shapes Earth's surface

How we explain it

Children can open this short lesson before they practice.

  1. Fossils, matching continents and rock layers show Earth has changed over time.
  2. Plates move slowly, about as fast as fingernails grow.
  3. Plates spreading apart form ocean basins; colliding plates build mountains and cause earthquakes and volcanoes.

Example: Sea shell fossils are found high in mountains. What does this show? Shells form in the sea. Plate movement pushed the rock upward. Answer: the rock formed under the sea and was pushed up

Plate Tectonics in Texas

In the Texas Essential Knowledge and Skills (TEKS), this is unit 18 of 18 in 7th grade Science, after Asexual & Sexual Reproduction.

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: Texas Education Agency (TEA)

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

    The law of superposition says that in undisturbed rock layers…

    • the oldest layers are on top
    • layers form sideways
    • all layers are the same age
    • the oldest layers are at the bottom

  2. Question 2

    Where two plates pull apart under the ocean, new sea floor forms at a…

    • hot spot
    • delta
    • mid-ocean ridge
    • deep trench

  3. Question 3

    South America and Africa fit together like puzzle pieces. This is evidence that…

    • Earth is getting smaller
    • the oceans are shrinking
    • the continents were once joined
    • plates never move

  4. Question 4

    When two continental plates collide, they form…

    • new oceans
    • tall mountain ranges
    • hot spots
    • river deltas

  5. Question 5

    Sea shell fossils high in a mountain range show…

    • the shells fell from the sky
    • sea animals climbed mountains
    • the rock formed under the sea and was later pushed up
    • the mountain is very young

  6. Question 6

    Rocks on the sea floor are youngest…

    • near continents
    • in the middle of plates
    • in trenches only
    • near mid-ocean ridges

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