Chemistry C2

Materials from rocks:

• Aluminium and iron from ores
• Brick from clay
• Glass from sand

Hardness of rocks:

• Limestone is a sedimentary rock
• marble is a metamorphic rock made from limestone that has been put under pressure and heated which makes it harder
• Granite is an igneous rock

Limestone is the easiest to shape because it's the softest and granite is the hardest to shape.

Limestone, cement and concrete

Limestone and marble are mainly made from calcium carbonate:

CaCO3 ---> CaO + CO2

This type of reaction is a thermal decomposition reaction; one material breaks down into two or more substances when heated.

Cement is made when limestone and clay are heated. Reinforced concrete is a composite material. Reinforced concrete is a better construction material because:

•  Of the hardness of the concrete
• The flexibility and strength of the steel

Movement of the lithosphere

The lithosphere is the relatively cold and rigid…