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Science 7

Science 7 · Worksheets

Mixed review · Heat, structures and Earth

Ten questions of mixed difficulty, covering Heat and temperature, Planet Earth, Structures and forces. Print it, or work through it on screen — the answer key starts on its own page.

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Mixed review · Heat, structures and Earth

Science 7 · maddyhelps.com

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Circle the best answer for each question. Show your work in the space provided.

  1. Engineers say a crowd jumping in time at a concert is harder on a balcony than the same crowd standing still. Why?

    1. a) Jumping turns the compression in the balcony into torsion
    2. b) Jumping adds mass to each person, so the crowd weighs more
    3. c) A crowd standing still puts no force on the balcony at all
    4. d) A moving, dynamic load can push harder than the same weight at rest

  2. Lava pours out of a volcano and cools quickly in the air, forming rock with crystals too small to see. This rock is

    1. a) sedimentary
    2. b) intrusive igneous
    3. c) metamorphic
    4. d) extrusive igneous

  3. A square frame of four sticks, pinned at the corners, folds sideways when pushed. Adding one stick from corner to corner stops this. Why?

    1. a) It splits the square into triangles, which cannot change shape
    2. b) It adds another side, and more sides make a shape stronger
    3. c) It lets the frame bend a little without the pins pulling out
    4. d) It makes the frame heavier, so a push has less effect

  4. Some people say turning the thermostat down at night saves nothing, because the furnace must warm the house up again in the morning. Why does it still save energy?

    1. a) A furnace burns its fuel more efficiently at night
    2. b) Heat flows into the house from outside overnight
    3. c) A cooler house loses heat to the cold outdoors more slowly
    4. d) Cold air holds more thermal energy than warm air does

  5. The Royal Tyrrell Museum is near Drumheller, in the badlands of the Red Deer River valley, where many dinosaur fossils have been found. Why are fossils found there more easily than on most of the flat prairie?

    1. a) Dinosaurs lived only in the Drumheller area and nowhere else in Alberta
    2. b) Erosion has cut down through the rock, exposing layers from the time of the dinosaurs
    3. c) The badlands rock is igneous, which preserves bones better than other rock
    4. d) Glaciers carried the dinosaur bones there from the Rocky Mountains

  6. Water seeps into a crack in a boulder, freezes and expands. Over many winters, the boulder splits apart. This is

    1. a) erosion
    2. b) deposition
    3. c) chemical weathering
    4. d) mechanical weathering

  7. A flat sheet of thin cardboard sags when you hold it by one edge, but corrugated cardboard, with a wavy layer glued between two flat sheets, stays stiff. Why?

    1. a) The folds act like many small arches and beams that resist bending
    2. b) The wavy layer adds so much weight that the sheet cannot sag
    3. c) The wavy layer is made of a much stronger kind of paper
    4. d) The glue between the layers is stiffer than the cardboard

  8. A canyon wall shows four flat, undisturbed layers of rock: sandstone on top, then shale, then limestone, then conglomerate at the bottom. Which layer formed first?

    1. a) The sandstone
    2. b) The limestone
    3. c) The shale
    4. d) The conglomerate

  9. A cliff shows four flat rock layers, numbered 1 at the bottom to 4 at the top. A band of igneous rock, called a dike, cuts up through layers 1, 2 and 3. Layer 4 lies unbroken across the top of the dike. What is the order of events?

    1. a) Layer 4, then layers 3, 2 and 1, then the dike
    2. b) Layers 1, 2, 3 and 4, then the dike
    3. c) Layers 1, 2 and 3, then the dike, then layer 4
    4. d) The dike, then layers 1, 2, 3 and 4

  10. Big Rock, near Okotoks, is a huge boulder sitting alone on flat prairie. It is made of a kind of rock found in the Rocky Mountains, not in the ground around it. How did it most likely get there?

    1. a) A glacier carried it and left it behind when the ice melted
    2. b) A river rolled it across the prairie during a flood
    3. c) A volcano nearby threw it out during an eruption
    4. d) The softer rock around it wore away and left it standing

Answer key · Mixed review · Heat, structures and Earth

Science 7 · maddyhelps.com

  1. d) A moving, dynamic load can push harder than the same weight at rest — A load that moves or changes is dynamic: each landing pushes down with more force than the person's weight, and jumping in rhythm can make a structure sway more and more. The people's mass never changes; the forces they put on the balcony do.
  2. d) extrusive igneous — Rock that forms when melted rock cools is igneous, and cooling fast at the surface gives crystals no time to grow, which makes extrusive rock such as basalt fine-grained. Intrusive igneous rock, such as granite, cools slowly underground and has large crystals.
  3. a) It splits the square into triangles, which cannot change shape — Once a triangle's three sides are fixed, its shape is fixed, so it cannot fold unless a side stretches or squashes. A square's corners can swing even when all four sides stay the same length, which is why towers, bridges and roof trusses are built of triangles.
  4. c) A cooler house loses heat to the cold outdoors more slowly — Heat leaks out faster when the difference between inside and outside is bigger, so a house kept cooler overnight loses less energy in total, even counting the morning warm-up. The furnace only ever replaces heat that has leaked away, so less leaking means less fuel.
  5. b) Erosion has cut down through the rock, exposing layers from the time of the dinosaurs — Across most of the prairie, the dinosaur-age rock lies buried under soil and younger deposits. In the badlands, water has worn the land into steep, bare slopes, so the old layers are exposed and erosion keeps uncovering new bones.
  6. d) mechanical weathering — Freezing water pries the rock apart without changing what it is made of, so this is mechanical weathering. Erosion is the next step, when the broken pieces are carried away by water, wind, ice or gravity.
  7. a) The folds act like many small arches and beams that resist bending — Corrugation turns a floppy sheet into a row of tiny arches and beams standing on edge, so bending it means squashing and stretching every fold at once. The paper is the same; only its shape changed, which is also why corrugated metal is used for roofs and culverts.
  8. d) The conglomerate — Sediment settles one layer on top of another, so in undisturbed layers the lowest was laid down first and the top one last. Reading the wall like a page, from the top down, gives the youngest layer instead of the oldest.
  9. c) Layers 1, 2 and 3, then the dike, then layer 4 — Magma can only cut through rock that is already there, so the dike is younger than layers 1 to 3, and layer 4, lying unbroken on top of it, came after the dike. Thinking the dike must be oldest because it reaches the bottom layer is the usual mistake.
  10. a) A glacier carried it and left it behind when the ice melted — Glaciers can carry boulders a very long way and drop them where the ice melts; a boulder moved like this is called a glacial erratic. It cannot be left over from worn-away rock, because it is a different kind of rock from the ground it sits on.