A) 10.0g of Iron is

of Iron.
One mole of dihydrogen is required to form one mole of iron, hence you'll need

of dihydrogen.
B) Likewise : 2.50g of Iron is

of Iron, hence we'll need

of Fe2O3.
<h2><u>
Answer:</u></h2>
C: They should try to reproduce Dr. Maxwell's research to verify his results
<h2><u>
Why?</u></h2>
Other scientists may or may not agree to Dr. Maxwell, so they should test Dr. Maxwell's research again to see if his conclusion is true or not.
Hope this helps!
It has many different uses like being used to make the tube of a vacuum cleaner and also can be used to make oil in space crafts.