C1 Topic 2 - Materials from the Earth Flashcards
Describe how igneous rocks are formed.
Igneous rocks form when molten magma pushes up into the crust before cooling and solidifying either above ground or below ground.
Describe how sedimentary rocks are formed and what they contain.
Sedimentary rocks are formed from layers of sediment laid down in lakes or seas. The layers get buried under more layers and the weight pressing down squeezes out the water. Sedimentary rocks contain fossils.
Describe how metamorphic rocks are formed.
Metamorphic rocks are formed by heat and pressure on sedimentary or igneous rocks over long periods of time.
How easily do different rock types erode?
Limestone and chalk are easily broken away by wind, rain and waves. Metamorphic rocks aren’t easily broken away because they are hard. Igneous rocks are hard and aren’t easily broken away.
What are some uses of limestone?
Limestone is used as a building material, in cement and glass.
Describe the advantages of quarrying limestone.
Limestone is used in houses, roads, dyes, paints, medicines and it is used to neutralise acidic soil.
Describe thermal decomposition of calcium carbonate.
Heat the carbonate in a boiling tube and pipe off the gas into a test tube filled with water, the limewater will turn milky.
Describe how cement, concrete and glass are made.
Powdered limestone is heated in a kiln with powdered clay to produce cement. Mix the cement with sand, water and gravel to make concrete. Heat limestone with sand and sodium carbonate until it melts to make glass.
Describe the reactions of calcium compounds.
When limestone is heated it thermally decomposes to form calcium oxide and carbon dioxide. When you add water to calcium oxide you get calcium hydroxide.
Give examples of igneous, sedimentary and metamorphic rocks.
Limestone and chalk are sedimentary rocks. Marble is a metamorphic rock. Basalt and granite are igneous rocks.
