Types of Rocks
What are the three main types of rocks?
Igneous, sedimentary and metamorphic.
What is molten rock beneath Earth’s surface called?
Magma.
Name the three main types of soil.
Clayey, loamy and sandy soil.
What process breaks rocks into smaller pieces?
Weathering.
Which type of rock is formed when magma or lava cools?
Igneous rock
What is magma called when it reaches Earth’s surface?
Lava.
Which soil is mostly made of sand particles?
Sandy soil.
What process moves weathered rock particles from one place to another?
Erosion.
Which type of rock often contains fossils?
Sedimentary rock.
Where are intrusive igneous rocks formed?
Underground.
Which soil holds water for a long time because it has very small particles?
Clayey soil.
Name the three types of weathering
Physical, chemical and biotic weathering.
Marble is an example of which type of rock?
Metamorphic rock.
Which type of igneous rock forms when lava cools on Earth’s surface?
Extrusive igneous rock.
Which type of soil has the best drainage?
Sandy soil.
Plant roots grow into cracks and break rocks apart. What type of weathering is this?
Biotic weathering.
Granite is an example of which type of igneous rock?
Intrusive igneous rock.
Does slow cooling produce large or small crystals?
Large crystals.
Which soil is usually best for growing plants?
Loamy soil.
Changes in temperature cause rocks to expand, contract and crack. What type of weathering is this?
Physical weathering.
Sandstone belongs to which main type of rock?
Sedimentary rock.
Why do extrusive igneous rocks have small crystals?
Because the lava cools quickly.
What is humus?
Decayed organic matter in soil.
What is the main difference between weathering and erosion?
Weathering breaks rocks down; erosion moves the broken material.
What metamorphic rock can form from limestone?
Marble.
Which cools more slowly: magma underground or lava on the surface?
Magma underground.
Why does clayey soil have poor drainage?
Its particles are very small and closely packed, so water passes through slowly.
How do sediments eventually become sedimentary rock?
They are compacted and cemented together.
What metamorphic rock can form from sandstone?
Quartzite.
Compare intrusive and extrusive igneous rocks based on crystal size.
Intrusive rocks have larger crystals; extrusive rocks have smaller crystals.
Why is loamy soil better for many plants than sandy or clayey soil?
It holds enough water but also allows excess water to drain.
How can igneous rock eventually become sedimentary rock?
Weathering and erosion → sediments → compaction and cementation → sedimentary rock.
A rock has visible layers and contains a fossil. What type of rock is it most likely to be, and why?
Sedimentary rock because sedimentary rocks form in layers and can contain fossils.
Two igneous rocks formed from molten material. Rock A has large crystals and Rock B has tiny crystals. Which one probably formed underground? Explain.
Rock A, because magma cools slowly underground, allowing large crystals to form.
A farmer needs soil that holds enough water for roots but does not become waterlogged. Which soil should they choose and why?
Loamy soil because it holds water while still allowing good drainage.
Describe one possible path through the rock cycle from magma to metamorphic rock.
Magma cools → igneous rock → weathering and erosion → sediments → compaction and cementation → sedimentary rock → heat and pressure → metamorphic rock.