5 moles.
think about the ratio of moles of iron oxide (Fe2O3) and iron (Fe) in that balanced chemical equation, which is 1:2, respectively. if there are 10 moles of Fe, you would divide that by 2 to get the number of moles of Fe2O3.
Answer:
B) 0.025 
Explanation:
Solution of the problem is in picture attached,
Answer:
You take the atomic, or proton number of the element, and you subtract it from the element's mass number.