Year 8 Science • AC9S8U04 • Authored homework
Rocks, Minerals and the Rock Cycle
Use the rock cycle to explain how igneous, sedimentary and metamorphic rocks form and change over time. Answer in full sentences where useful, and use evidence or examples in longer responses.
Part A
Short-answer questions
Name the three main rock types.
How does an igneous rock form?
How does a sedimentary rock form?
How does a metamorphic rock form?
What is weathering?
What is erosion?
Explain the difference between melting and cooling in the rock cycle.
Why are fossils more likely to be found in sedimentary rock than igneous rock?
Give one example of a mineral property used to identify a rock or mineral.
Write one sentence explaining why the rock cycle is a cycle rather than a straight line.
Part B
Long-answer questions
Explain how sediment can become sedimentary rock. Include weathering, erosion, deposition, compaction and cementation.
Describe how an igneous rock can eventually become a metamorphic rock.
Compare intrusive and extrusive igneous rocks and explain how cooling rate affects crystal size.
A student says, “A rock stays the same forever.” Use the rock cycle to evaluate this claim.
Explain how heat and pressure can change a rock without melting it completely.
Use a labelled flow chart to show at least four pathways a rock can take through the rock cycle.
Explain how the rock cycle links surface processes with processes deep inside Earth.
Interpret a rock sample that contains visible layers and fossil fragments. What type of rock is it likely to be and why?
Describe how mining or quarrying can reveal information about rock formation and Earth history.
Write a full explanation of how energy from the Sun and energy from inside Earth both drive parts of the rock cycle.
Part C
Research and understanding task
Research one rock used in buildings, roads, jewellery or technology. Identify its rock type, how it formed and why its properties make it useful.