Zusammenfassung der Ressource
Materials from the Earth
- C1.5 Rocks & Their Formation
- igneous rocks
- solidification of magma/lava
- interlocking crystals
- slower cooling = larger crystals
- e.g. granite
- sedimentary rocks
- layers of sediment compacted
- erode easily
- may contain fossils
- e.g. chalk & limestone
- metamorphic rocks
- from existing rocks by heat/pressure
- e.g. marble from chalk/limestone
- C1.6 Limestone & Its Uses
- uses
- concrete/cement/glass
- construction
- steel/iron alloys
- quarrying
- advantages
- provides jobs
- limestone=important raw material
- exported-aids UK economy
- jobs help local economies
- disadvantages
- spoils scenery
- lorries produce noise/pollution/traffic
- dust/noise
- destroys habitats
- thermal decomposition
- CaCO3 --> CaO + CO2
- C1.8 Chemical Reactions
- thermal decomposition
- copper carbonate = easiest
- zinc carbonate
- calcium carbonate = hardest
- atoms
- smallest particle of element
- take part in reactions
- not created/destroyed
- rearranged
- mass
- remains the same in sealed container
- precipitation reaction
- 2 soluble reactants form insoluble precipitate
- C1.9 Reactions of Calcium Compounds
- making limewater
- 1. CaCO3 --> CaO+CO2
- 2. CaO+H2O --> Ca(OH)2
- fizzing,steam,heat
- 3. Ca(OH)2+CO2 --> CaCO3+H2O
- when CO2 is bubbled through calcium hydroxide limewater is produced
- neutralising acids
- calcium compounds neutralise acids
- e.g. in soil
- e.g. in power stations to get rid of sulphur dioxide and nitrogen oxides
- this reduces acid rain