Concept:In its free elemental state, any atom has an oxidation number of
0 because it is not bonded to a different element.
Explanation:Iron metal consists of neutral iron atoms.
Oxidation number is the hypothetical charge on an atom in a compound if electrons were assigned according to electronegativity.
For an uncombined element, there is no electron transfer or unequal sharing of electrons.
Therefore, iron atoms carry no charge, and its oxidation number is
0.
Although iron commonly forms ions like
Fe2+ or
Fe3+ in compounds, this question refers to iron in its free state.
So the correct option is the one that gives the oxidation number as zero.
Answer:A.
0