Igneous Rocks - Studyladder Interactive Learning Games - Free Printable

Let's solve this worksheet step by step. This is a science worksheet about volcanic rocks and volcanoes, designed for students to learn about igneous rocks, volcanic activity, and the structure of a volcano.

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🔹 Part 1: Fill in the Blanks

> Rocks that are formed by volcanic activity are called ________ rocks.
✔ Answer: *igneous*
*(Igneous rocks form from cooled magma or lava.)*

> When lava cools it _________.
✔ Answer: *solidifies*
*(Lava turns solid when it cools.)*

> Lava that contains a lot of gas will solidify into very light-weight rocks like ________ or scoria.
✔ Answer: *pumice*
*(Pumice and scoria are lightweight volcanic rocks full of gas bubbles.)*

> Lava that cools ________ has closely packed fine particles, like basalt.
✔ Answer: *quickly*
*(Fast cooling leads to small crystals or no visible crystals — like in basalt.)*

> Lava that cools very slowly often contains lots of ________, like granite.
✔ Answer: *crystals*
*(Slow cooling allows large crystals to grow — typical in granite.)*

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🔹 Part 2: Circle the Correct Answers

> Which is heavier?
a) granite b) pumice
✔ Answer: *granite*
*(Pumice is so light it can float on water; granite is dense.)*

> Which is harder?
a) scoria b) basalt
✔ Answer: *basalt*
*(Basalt is denser and more compact than scoria, which is porous.)*

> Which has more crystals?
a) basalt b) granite
✔ Answer: *granite*
*(Granite cools slowly underground → large crystals. Basalt cools quickly → tiny crystals.)*

> Which solidifies faster?
a) granite b) basalt
✔ Answer: *basalt*
*(Basalt forms from lava on the surface → cools fast. Granite forms deep underground → cools slowly.)*

> Which has more air bubbles?
a) pumice b) basalt
✔ Answer: *pumice*
*(Pumice is full of gas bubbles trapped during rapid cooling.)*

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🔹 Part 3: Draw and Label

> How is pumice used?
✔ Answer (example):
- Used as a natural abrasive (e.g., in skincare scrubs).
- Lightweight building material.
- In gardening (for drainage).

> How is granite used?
✔ Answer (example):
- Countertops and flooring.
- Building stone.
- Monuments and sculptures.

*(Students should draw simple illustrations showing these uses.)*

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🔹 Part 4: Label the Main Parts of a Volcano

The diagram shows a cross-section of a volcano. Here are the labels:

1) Lava – molten rock that flows out of the volcano
2) Vent – the opening through which lava erupts
3) Crater – the bowl-shaped depression at the top
4) Magma chamber – where magma collects beneath the surface
5) Dike or fault line – a crack in rock where magma moves upward
6) Lava flow – the stream of lava moving down the slope

> ✔ Correct Labels (with blanks filled):
1) lava
2) vent
3) crater
4) magma chamber
5) dike or fault line
6) lava flow

*(Note: The diagram may vary slightly, but these are standard parts.)*

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🔹 Part 5: Write – Explain how magma finds its way to the Earth’s crust.

✔ Sample Answer:
Magma forms deep underground in the mantle when rocks melt due to high temperature and pressure. It rises toward the Earth’s crust because it is less dense than the surrounding solid rock. Magma moves upward through cracks and weaknesses in the crust, sometimes forming a magma chamber. When pressure builds up, the magma can erupt through a vent, becoming lava on the surface. This process is driven by convection currents in the mantle and the buoyancy of the molten rock.

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✔ Final Summary of Answers:

#### Fill in the Blanks:
- igneous
- solidifies
- pumice
- quickly
- crystals

#### Multiple Choice:
- Heavier: granite
- Harder: basalt
- More crystals: granite
- Solidifies faster: basalt
- More air bubbles: pumice

#### Diagram Labels:
1. Lava
2. Vent
3. Crater
4. Magma chamber
5. Dike/fault line
6. Lava flow

#### Uses:
- Pumice: Skincare scrub, lightweight concrete, drainage in gardens
- Granite: Countertops, buildings, monuments

#### Explanation:
Magma rises due to buoyancy and pressure, moving through cracks in the crust until it reaches the surface via a volcano.

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Let me know if you'd like a printable version or help with drawing the diagrams!