Answer:
I guess A, I am not sure...
So your answer would pretty much be 2.80 x 10^24. The picture is just the explanation and how you would get that answer.
10 is mixture of elements and compounds
11 is compound
12-15 are mixture of compounds
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Carbon is used to reduce the oxide of aluminium to get the metal, in case condensation happens during this process.
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Hope this helps!