Given the chemical equation: Fe2O3 + 3CO --> 2Fe + 3CO2

You need to make 112 g of iron (Fe). You have as much carbon monoxide (CO) as needed. How much iron oxide (Fe2O3) do you need to start with?

The answer to your question is 160 g of Fe₂O₃  

Explanation:

Data

mass of Fe = 112 g

mass of CO = in excess

mass of Fe₂O₃ = ?

Balanced chemical reaction

                Fe₂O₃  +  3CO  ⇒  2Fe  +  3CO₂

Process

1.- Calculate the molar mass of Fe₂O₃ and Fe

Molar mass Fe₂O₃ = (56 x 2) + (16 x 3) = 112 + 48 = 160 g

atomic mass of Fe = 56

2.- Use proportions to calculate the mass of Fe₂O₃ needed

                160 g of Fe₂O₃ 2(56) g of Fe

                 x     g of Fe₂O₃ 112 g of Fe

                 x = (112 x 160) / 2(56)

                 x = 17920/112

                 x = 160 g of Fe₂O₃          

it's c. elements are placed in rows based on how may valencies electrons have.

metals are good conductor of electricity. it has free electrons on their surface. according to electron pool theory, each atom present in a metal crystal losses all of its valence electron and as a result a pool of free is form. these pool of electrons are free to move and   conduct electricity easily   while making metal as good conductor.

the correct answer is a. the ability of electrons to flow throughout the metal.

if it's not useful, feel free to report for mistake in answer.