Iron react with oxygen to form Iron (III) Oxide. How many moles of iron (III) Oxide is in 138.5g?

0.87mole

Explanation:

The reaction equation is given as;

    4Fe + 3O₂  →  2Fe₂O₃

Number of moles of Fe₂O₃ in 138.5g

To solve this problem;

 Number of moles =

Molar mass of Fe₂O₃ = 2(56) + 3(16) = 160g/mol

 Now;

          Number of moles  =   = 0.87mole

d) a person who learns about the world by observing it.

explanation:

scientist are people who discover why and how things are done and made in the world.