Question 5 is the second one.
Answer:
CuFeS2
Explanation:
Calculate the moles of each substance by doing moles= mass/relative atomic mass. you should get 0.25 moles of copper and iron and 0.5 moles of sulfur. Then divide all of those numbers by 0.25 (as its the lowest value) you should get 1 for copper and iron and 2 for sulfur. This represents the ratio that they are in within the mineral.
