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. Which lightweight volcanic igneous rock is so full of trapped gas bubbles that it can float on water: pumice or marble?
Topsoil → Subsoil → Bedrock
2. In which type of rock are fossils of ancient plants and animals almost always found: sedimentary rock or igneous rock?
Topsoil → Subsoil → Bedrock
3. 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
4. What do we call a rock that does NOT allow water to pass through it because its crystals interlock tightly without gaps (such as granite or slate): an impermeable rock or a permeable rock?
Topsoil → Subsoil → Bedrock
5. 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
6. What is soil made of: a mixture of weathered rock particles (sand, silt, clay), decaying organic matter (humus), water, air and living organisms, or pure crushed glass?
Topsoil → Subsoil → Bedrock
7. What is the difference between “weathering” and “erosion” of rocks: weathering is the breakdown of rock in place, whereas erosion is the wearing away and transport of rock fragments by water, wind or ice, or they mean melting?
Topsoil → Subsoil → Bedrock
8. How do earthworms help keep garden and farm soil healthy for plants: their burrows let air and rainwater reach roots, and their castings enrich the soil with nutrients, or they eat rocks into lava?
Topsoil → Subsoil → Bedrock
9. Which soil type has large, gritty particles with big air spaces so water drains through it very quickly: sandy soil or clay soil?
Topsoil → Subsoil → Bedrock
10. 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
11. 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
12. What is the dark, nutrient-rich organic material in topsoil formed from decomposed leaves, roots and animal remains: humus or magma?
Topsoil → Subsoil → Bedrock
12 questions · Seed 47 · 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. Which lightweight volcanic igneous rock is so full of trapped gas bubbles that it can float on water: pumice or marble?
Pumice
Pumice forms from frothy lava rich in gas bubbles, giving it a density lower than water.
2. In which type of rock are fossils of ancient plants and animals almost always found: sedimentary rock or igneous rock?
Sedimentary rock
Sedimentary layers gently bury remains in mud or sand; the extreme heat of magma destroys fossils in igneous rock.
3. 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.
4. What do we call a rock that does NOT allow water to pass through it because its crystals interlock tightly without gaps (such as granite or slate): an impermeable rock or a permeable rock?
Impermeable rock
Impermeable rocks block water from soaking through, making slate ideal for roof tiles.
5. 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.
6. What is soil made of: a mixture of weathered rock particles (sand, silt, clay), decaying organic matter (humus), water, air and living organisms, or pure crushed glass?
A mixture of weathered rock particles (sand, silt, clay), decaying organic matter (humus), water, air and living organisms
Healthy soil combines mineral particles from weathered rock with organic humus, air spaces and water.
7. What is the difference between “weathering” and “erosion” of rocks: weathering is the breakdown of rock in place, whereas erosion is the wearing away and transport of rock fragments by water, wind or ice, or they mean melting?
Weathering is the breakdown of rock in place, whereas erosion is the wearing away and transport of rock fragments by water, wind or ice
Weathering breaks rock down in situ; erosion moves the loosened sediment away.
8. How do earthworms help keep garden and farm soil healthy for plants: their burrows let air and rainwater reach roots, and their castings enrich the soil with nutrients, or they eat rocks into lava?
Their burrows let air and rainwater reach roots, and their castings enrich the soil with nutrients
Earthworms aerate the soil, improve drainage and recycle organic matter into plant nutrients.
9. Which soil type has large, gritty particles with big air spaces so water drains through it very quickly: sandy soil or clay soil?
Sandy soil
Sand grains are relatively large, creating wide pore spaces that drain water rapidly.
10. 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.
11. 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.
12. What is the dark, nutrient-rich organic material in topsoil formed from decomposed leaves, roots and animal remains: humus or magma?
Humus
Humus retains moisture and supplies essential mineral nutrients to growing plant roots.
12 questions · Seed 47 · Age guidance, not curriculum certification
Worksheet StudioPractice pack · Ages 10-12
Rocks, fossils & soil layers
Take your time. Show your thinking.
1. Which lightweight volcanic igneous rock is so full of trapped gas bubbles that it can float on water: pumice or marble?
Topsoil → Subsoil → Bedrock
2. In which type of rock are fossils of ancient plants and animals almost always found: sedimentary rock or igneous rock?
Topsoil → Subsoil → Bedrock
3. 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
4. What do we call a rock that does NOT allow water to pass through it because its crystals interlock tightly without gaps (such as granite or slate): an impermeable rock or a permeable rock?
Topsoil → Subsoil → Bedrock
5. 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
6. What is soil made of: a mixture of weathered rock particles (sand, silt, clay), decaying organic matter (humus), water, air and living organisms, or pure crushed glass?
Topsoil → Subsoil → Bedrock
7. What is the difference between “weathering” and “erosion” of rocks: weathering is the breakdown of rock in place, whereas erosion is the wearing away and transport of rock fragments by water, wind or ice, or they mean melting?
Topsoil → Subsoil → Bedrock
8. How do earthworms help keep garden and farm soil healthy for plants: their burrows let air and rainwater reach roots, and their castings enrich the soil with nutrients, or they eat rocks into lava?
Topsoil → Subsoil → Bedrock
9. Which soil type has large, gritty particles with big air spaces so water drains through it very quickly: sandy soil or clay soil?
Topsoil → Subsoil → Bedrock
10. 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
11. 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
12. What is the dark, nutrient-rich organic material in topsoil formed from decomposed leaves, roots and animal remains: humus or magma?
Topsoil → Subsoil → Bedrock
12 questions · Seed 47 · Age guidance, not curriculum certification
Worksheet StudioAnswer key · Ages 10-12
Rocks, fossils & soil layers
Answers and reasoning. Review before teaching.
1. Which lightweight volcanic igneous rock is so full of trapped gas bubbles that it can float on water: pumice or marble?
Pumice
Pumice forms from frothy lava rich in gas bubbles, giving it a density lower than water.
2. In which type of rock are fossils of ancient plants and animals almost always found: sedimentary rock or igneous rock?
Sedimentary rock
Sedimentary layers gently bury remains in mud or sand; the extreme heat of magma destroys fossils in igneous rock.
3. 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.
4. What do we call a rock that does NOT allow water to pass through it because its crystals interlock tightly without gaps (such as granite or slate): an impermeable rock or a permeable rock?
Impermeable rock
Impermeable rocks block water from soaking through, making slate ideal for roof tiles.
5. 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.
6. What is soil made of: a mixture of weathered rock particles (sand, silt, clay), decaying organic matter (humus), water, air and living organisms, or pure crushed glass?
A mixture of weathered rock particles (sand, silt, clay), decaying organic matter (humus), water, air and living organisms
Healthy soil combines mineral particles from weathered rock with organic humus, air spaces and water.
7. What is the difference between “weathering” and “erosion” of rocks: weathering is the breakdown of rock in place, whereas erosion is the wearing away and transport of rock fragments by water, wind or ice, or they mean melting?
Weathering is the breakdown of rock in place, whereas erosion is the wearing away and transport of rock fragments by water, wind or ice
Weathering breaks rock down in situ; erosion moves the loosened sediment away.
8. How do earthworms help keep garden and farm soil healthy for plants: their burrows let air and rainwater reach roots, and their castings enrich the soil with nutrients, or they eat rocks into lava?
Their burrows let air and rainwater reach roots, and their castings enrich the soil with nutrients
Earthworms aerate the soil, improve drainage and recycle organic matter into plant nutrients.
9. Which soil type has large, gritty particles with big air spaces so water drains through it very quickly: sandy soil or clay soil?
Sandy soil
Sand grains are relatively large, creating wide pore spaces that drain water rapidly.
10. 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.
11. 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.
12. What is the dark, nutrient-rich organic material in topsoil formed from decomposed leaves, roots and animal remains: humus or magma?
Humus
Humus retains moisture and supplies essential mineral nutrients to growing plant roots.
12 questions · Seed 47 · Age guidance, not curriculum certification