KO: Types of Rocks
Subject: Science | Year: 3
Name: _________________________ Class/Set: ____________ Date: ____________
1. Key Knowledge / Core Facts
- Geologist: A scientist who studies the Earth and what it is made of.
- The Rock Cycle: The slow process of rocks changing from one type to another over millions of years.
- Magma: Molten (liquid) rock found deep beneath the Earth's surface.
- Lava: Molten rock that has erupted from a volcano onto the surface.
- Erosion: The wearing away of rocks by wind, water, or ice.
- Properties: The features of a rock, such as how hard it is or if it soaks up water.
2. Key Vocabulary
- Permeable: Describes a rock that allows water to soak through it.
- Impermeable: Describes a rock that does not allow water to pass through.
- Durable: A rock that is hard-wearing and does not break easily.
- Sediment: Small pieces of rock, sand, and minerals that settle at the bottom of water.
- Pressure: The force of weight pushing down on something.
- Crystals: Shiny, flat-sided minerals found inside many types of rock.
3. Igneous Rocks (Fire Rocks)
- Formation: Created when magma or lava cools down and turns into solid rock.
- Appearance: Often very hard and may contain shiny crystals.
- Granite: Contains large crystals; used for durable kitchen worktops.
- Basalt: A dark, heavy rock formed from lava cooling on the surface.
- Pumice: Formed from lava with air bubbles; it is light enough to float.
- Obsidian: Volcanic glass that is very shiny and sharp.
4. Sedimentary Rocks (Layered Rocks)
- Formation: Layers of sediment build up over millions of years and are squashed together.
- Fossils: These are the only types of rock where you can find fossils.
- Chalk: A soft, white rock made from the remains of tiny sea creatures.
- Sandstone: Formed from grains of sand; it feels gritty to the touch.
- Limestone: A grey rock often used for building; it reacts to acid.
- Shale: A smooth, flaky rock formed from mud or clay.
5. Metamorphic Rocks (Changed Rocks)
- Formation: Existing rocks changed by extreme heat and heavy pressure.
- Transformation: 'Metamorphosis' means to change from one thing into another.
- Marble: Formed from limestone; used for beautiful statues and floors.
- Slate: Formed from shale; it splits into thin sheets, perfect for roof tiles.
- Quartzite: An extremely hard rock that was once sandstone.
- Schist: Often has a 'glittery' or wavy appearance due to high pressure.
6. Check Your Knowledge
- Task 1: The Fossil Finder: Identify which of the three rock groups is the only one to contain fossils.
- Task 2: Property Check: Explain why a builder would choose slate for a roof instead of chalk.
- Task 3: Formation Match-Up: Describe the difference between how magma and lava form igneous rocks.
⚠ TEACHER’S GUIDANCE
💡 Pedagogical Insights & Delivery tips
- Identify Misconceptions: Students often believe rocks are "unchanging." Emphasise the Rock Cycle as a process of recycling over millions of years.
- Sensory Engagement: Ensure students handle physical samples of pumice (weight/floating), sandstone (texture), and slate (cleavage/layering) to move from concrete to abstract understanding.
- Working Scientifically: Model: Show students how to perform a hardness test using a 2p coin and a permeability test using a pipette and water.
- ⚠ Safety & Nuance Check: When handling rocks like obsidian or flint, warn students about sharp edges. If using a 'fizz test' with weak acid (vinegar) on limestone, ensure safety goggles are worn.
🔑 Teacher’s Key & Mirror-Labeling
- Task 1 Answer (The Fossil Finder): Sedimentary rocks. Explanation: These rocks form at lower temperatures and pressures that allow animal and plant remains to be preserved in layers of sediment.
- Task 2 Answer (Property Check): Slate is used because it is impermeable (waterproof) and durable. Chalk is too soft, permeable, and would wear away quickly in the rain.
- Task 3 Answer (Formation Match-Up): Magma cools slowly underground to form intrusive igneous rocks with large crystals (e.g., Granite). Lava cools quickly on the surface to form extrusive igneous rocks with small or no crystals (e.g., Basalt).
