Compare igneous, sedimentary and metamorphic rocks, fossil formation, permeability and soil horizons. Review suitability for your learners before teaching.
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Worksheet StudioPractice pack · Ages 10-12
Rocks, fossils & soil layers
Take your time. Show your thinking.
1. On the Mohs hardness scale of minerals from 1 (softest, talc) to 10 (hardest), which natural mineral is the hardest (10) and can scratch all other minerals: diamond or chalk?
Topsoil → Subsoil → Bedrock
2. Why does intrusive igneous rock like granite have large, visible mineral crystals, whereas extrusive basalt has tiny crystals: granite cooled slowly deep underground, giving crystals time to grow, or granite is made of sand?
Topsoil → Subsoil → Bedrock
3. Which soil type has microscopic particles that pack tightly together, holding water and feeling sticky when wet: clay soil or sandy soil?
Topsoil → Subsoil → Bedrock
4. Which rock group forms over millions of years when layers of sand, mud, pebbles or shells are compacted and cemented together (such as sandstone, limestone and shale): sedimentary rock or igneous rock?
Topsoil → Subsoil → Bedrock
5. Which of the three main rock groups forms when molten magma or lava cools and solidifies (such as granite and basalt): igneous rock or sedimentary rock?
Topsoil → Subsoil → Bedrock
6. Which rock group forms when existing rocks are changed by intense heat and pressure deep underground without completely melting (such as marble from limestone, or slate from shale): metamorphic rock or sedimentary rock?
Topsoil → Subsoil → Bedrock
7. What are fossils: the preserved remains, shells, bones or impressions of ancient living things turned to stone over millions of years, or modern plastic models?
Topsoil → Subsoil → Bedrock
8. What do gardeners call an ideal balanced soil that mixes sand, silt, clay and humus so it holds moisture and nutrients while still draining well: loam or gravel?
Topsoil → Subsoil → Bedrock
9. What do we call a rock that has tiny connected pores or spaces that allow water to soak and pass through it (such as sandstone or chalk): a permeable (porous) rock or an impermeable rock?
Topsoil → Subsoil → Bedrock
10. When limestone is subjected to high heat and pressure inside Earth’s crust, what hard, crystalline metamorphic rock does it turn into (often used for statues and tiles): marble or sandstone?
Topsoil → Subsoil → Bedrock
11. In a vertical soil profile, which uppermost layer contains the most humus, plant roots and soil organisms like earthworms: topsoil (A horizon) or solid bedrock?
Topsoil → Subsoil → Bedrock
12. Why do pebbles on a beach or riverbed become smooth and rounded over time: waves and currents tumble the stones against each other, wearing off sharp corners by attrition and abrasion, or people polish every stone?
Topsoil → Subsoil → Bedrock
12 questions · Seed 44 · Age guidance, not curriculum certification
View the answer key
Worksheet StudioAnswer key · Ages 10-12
Rocks, fossils & soil layers
Answers and reasoning. Review before teaching.
1. On the Mohs hardness scale of minerals from 1 (softest, talc) to 10 (hardest), which natural mineral is the hardest (10) and can scratch all other minerals: diamond or chalk?
Diamond
Diamond ranks 10 on the Mohs hardness scale because of its strong three-dimensional covalent carbon lattice.
2. Why does intrusive igneous rock like granite have large, visible mineral crystals, whereas extrusive basalt has tiny crystals: granite cooled slowly deep underground, giving crystals time to grow, or granite is made of sand?
Granite cooled slowly deep underground, giving crystals time to grow
Slow cooling of magma underground allows large interlocking crystals to form; lava on the surface cools rapidly into tiny crystals.
3. Which soil type has microscopic particles that pack tightly together, holding water and feeling sticky when wet: clay soil or sandy soil?
Clay soil
Tiny clay particles have tiny pores that trap water and become sticky when wet and hard when baked dry.
4. Which rock group forms over millions of years when layers of sand, mud, pebbles or shells are compacted and cemented together (such as sandstone, limestone and shale): sedimentary rock or igneous rock?
Sedimentary rock
Sedimentary rocks form in layers (strata) from deposited and lithified sediments.
5. Which of the three main rock groups forms when molten magma or lava cools and solidifies (such as granite and basalt): igneous rock or sedimentary rock?
Igneous rock
Igneous rocks crystallise from molten rock either underground (magma) or on the surface (lava).
6. Which rock group forms when existing rocks are changed by intense heat and pressure deep underground without completely melting (such as marble from limestone, or slate from shale): metamorphic rock or sedimentary rock?
Metamorphic rock
“Metamorphic” means changed in form; heat and pressure recrystallise minerals into a denser rock.
7. What are fossils: the preserved remains, shells, bones or impressions of ancient living things turned to stone over millions of years, or modern plastic models?
The preserved remains, shells, bones or impressions of ancient living things turned to stone over millions of years
Fossils provide direct evidence of how organisms and environments have changed over geological time.
8. What do gardeners call an ideal balanced soil that mixes sand, silt, clay and humus so it holds moisture and nutrients while still draining well: loam or gravel?
Loam
Loamy soil combines the good drainage of sand with the moisture and nutrient retention of silt, clay and humus.
9. What do we call a rock that has tiny connected pores or spaces that allow water to soak and pass through it (such as sandstone or chalk): a permeable (porous) rock or an impermeable rock?
Permeable (porous) rock
Permeable rocks have interconnected pore spaces or fractures that let water percolate through.
10. When limestone is subjected to high heat and pressure inside Earth’s crust, what hard, crystalline metamorphic rock does it turn into (often used for statues and tiles): marble or sandstone?
Marble
Marble is metamorphosed limestone.
11. In a vertical soil profile, which uppermost layer contains the most humus, plant roots and soil organisms like earthworms: topsoil (A horizon) or solid bedrock?
Topsoil (A horizon)
Topsoil is the fertile surface layer where seeds germinate and most roots and decomposers live.
12. Why do pebbles on a beach or riverbed become smooth and rounded over time: waves and currents tumble the stones against each other, wearing off sharp corners by attrition and abrasion, or people polish every stone?
Waves and currents tumble the stones against each other, wearing off sharp corners by attrition and abrasion
Moving water knocks rock fragments together (attrition), rounding sharp edges into smooth pebbles and sand.
12 questions · Seed 44 · Age guidance, not curriculum certification
Worksheet StudioPractice pack · Ages 10-12
Rocks, fossils & soil layers
Take your time. Show your thinking.
1. On the Mohs hardness scale of minerals from 1 (softest, talc) to 10 (hardest), which natural mineral is the hardest (10) and can scratch all other minerals: diamond or chalk?
Topsoil → Subsoil → Bedrock
2. Why does intrusive igneous rock like granite have large, visible mineral crystals, whereas extrusive basalt has tiny crystals: granite cooled slowly deep underground, giving crystals time to grow, or granite is made of sand?
Topsoil → Subsoil → Bedrock
3. Which soil type has microscopic particles that pack tightly together, holding water and feeling sticky when wet: clay soil or sandy soil?
Topsoil → Subsoil → Bedrock
4. Which rock group forms over millions of years when layers of sand, mud, pebbles or shells are compacted and cemented together (such as sandstone, limestone and shale): sedimentary rock or igneous rock?
Topsoil → Subsoil → Bedrock
5. Which of the three main rock groups forms when molten magma or lava cools and solidifies (such as granite and basalt): igneous rock or sedimentary rock?
Topsoil → Subsoil → Bedrock
6. Which rock group forms when existing rocks are changed by intense heat and pressure deep underground without completely melting (such as marble from limestone, or slate from shale): metamorphic rock or sedimentary rock?
Topsoil → Subsoil → Bedrock
7. What are fossils: the preserved remains, shells, bones or impressions of ancient living things turned to stone over millions of years, or modern plastic models?
Topsoil → Subsoil → Bedrock
8. What do gardeners call an ideal balanced soil that mixes sand, silt, clay and humus so it holds moisture and nutrients while still draining well: loam or gravel?
Topsoil → Subsoil → Bedrock
9. What do we call a rock that has tiny connected pores or spaces that allow water to soak and pass through it (such as sandstone or chalk): a permeable (porous) rock or an impermeable rock?
Topsoil → Subsoil → Bedrock
10. When limestone is subjected to high heat and pressure inside Earth’s crust, what hard, crystalline metamorphic rock does it turn into (often used for statues and tiles): marble or sandstone?
Topsoil → Subsoil → Bedrock
11. In a vertical soil profile, which uppermost layer contains the most humus, plant roots and soil organisms like earthworms: topsoil (A horizon) or solid bedrock?
Topsoil → Subsoil → Bedrock
12. Why do pebbles on a beach or riverbed become smooth and rounded over time: waves and currents tumble the stones against each other, wearing off sharp corners by attrition and abrasion, or people polish every stone?
Topsoil → Subsoil → Bedrock
12 questions · Seed 44 · Age guidance, not curriculum certification
Worksheet StudioAnswer key · Ages 10-12
Rocks, fossils & soil layers
Answers and reasoning. Review before teaching.
1. On the Mohs hardness scale of minerals from 1 (softest, talc) to 10 (hardest), which natural mineral is the hardest (10) and can scratch all other minerals: diamond or chalk?
Diamond
Diamond ranks 10 on the Mohs hardness scale because of its strong three-dimensional covalent carbon lattice.
2. Why does intrusive igneous rock like granite have large, visible mineral crystals, whereas extrusive basalt has tiny crystals: granite cooled slowly deep underground, giving crystals time to grow, or granite is made of sand?
Granite cooled slowly deep underground, giving crystals time to grow
Slow cooling of magma underground allows large interlocking crystals to form; lava on the surface cools rapidly into tiny crystals.
3. Which soil type has microscopic particles that pack tightly together, holding water and feeling sticky when wet: clay soil or sandy soil?
Clay soil
Tiny clay particles have tiny pores that trap water and become sticky when wet and hard when baked dry.
4. Which rock group forms over millions of years when layers of sand, mud, pebbles or shells are compacted and cemented together (such as sandstone, limestone and shale): sedimentary rock or igneous rock?
Sedimentary rock
Sedimentary rocks form in layers (strata) from deposited and lithified sediments.
5. Which of the three main rock groups forms when molten magma or lava cools and solidifies (such as granite and basalt): igneous rock or sedimentary rock?
Igneous rock
Igneous rocks crystallise from molten rock either underground (magma) or on the surface (lava).
6. Which rock group forms when existing rocks are changed by intense heat and pressure deep underground without completely melting (such as marble from limestone, or slate from shale): metamorphic rock or sedimentary rock?
Metamorphic rock
“Metamorphic” means changed in form; heat and pressure recrystallise minerals into a denser rock.
7. What are fossils: the preserved remains, shells, bones or impressions of ancient living things turned to stone over millions of years, or modern plastic models?
The preserved remains, shells, bones or impressions of ancient living things turned to stone over millions of years
Fossils provide direct evidence of how organisms and environments have changed over geological time.
8. What do gardeners call an ideal balanced soil that mixes sand, silt, clay and humus so it holds moisture and nutrients while still draining well: loam or gravel?
Loam
Loamy soil combines the good drainage of sand with the moisture and nutrient retention of silt, clay and humus.
9. What do we call a rock that has tiny connected pores or spaces that allow water to soak and pass through it (such as sandstone or chalk): a permeable (porous) rock or an impermeable rock?
Permeable (porous) rock
Permeable rocks have interconnected pore spaces or fractures that let water percolate through.
10. When limestone is subjected to high heat and pressure inside Earth’s crust, what hard, crystalline metamorphic rock does it turn into (often used for statues and tiles): marble or sandstone?
Marble
Marble is metamorphosed limestone.
11. In a vertical soil profile, which uppermost layer contains the most humus, plant roots and soil organisms like earthworms: topsoil (A horizon) or solid bedrock?
Topsoil (A horizon)
Topsoil is the fertile surface layer where seeds germinate and most roots and decomposers live.
12. Why do pebbles on a beach or riverbed become smooth and rounded over time: waves and currents tumble the stones against each other, wearing off sharp corners by attrition and abrasion, or people polish every stone?
Waves and currents tumble the stones against each other, wearing off sharp corners by attrition and abrasion
Moving water knocks rock fragments together (attrition), rounding sharp edges into smooth pebbles and sand.
12 questions · Seed 44 · Age guidance, not curriculum certification