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We quarry large amounts of limestone rock because it has many uses.
Blocks of limestone can be used for buildings, and it is used to make:
Limestone is made up mainly of calcium carbonate, formula CaCO3 (small 3)
When heated strongly, calcium carbonate decomposes to make quicklime (calcium oxide, CaO)
and Carbon dioxide (CO2)
We can repersent the reaction by the word equation:
Calcium carbonate > calcium oxide + carbon dioxide
This is done on a large scale in lime kilns.