In the reaction \( 4\text{Fe} + 3\text{O}_2 \rightarrow 2\text{Fe}_2\text{O}_3 \), the following changes occur to the atoms of iron (Fe) and oxygen (O2):
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Reactants:
- Four atoms of iron (Fe) react with three molecules of oxygen (O2). Each molecule of O2 contains two oxygen atoms, so a total of six oxygen atoms are involved in the reaction.
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Products:
- The reaction produces two formula units of iron(III) oxide (Fe2O3). Each formula unit of Fe2O3 contains two iron atoms and three oxygen atoms. Therefore, two units of Fe2O3 contain a total of four iron atoms and six oxygen atoms.
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Conservation of Mass:
- The total number of atoms of each element is conserved during the reaction. This means that the four iron atoms and six oxygen atoms from the reactants re-arrange to form the four iron atoms and six oxygen atoms in the products.
In summary, the iron atoms combine with oxygen molecules to form iron(III) oxide, with no atoms lost or created in the process; they are merely rearranged.