Final answer:
The ratio of ferrite to cementite in iron-carbon alloys depends on the specific alloy. The atoms in iron oxide stick together due to ionic and covalent bonding, and iron oxide is composed of a combination of metal (iron) and nonmetal (oxygen) atoms.
Step-by-step explanation:
The student's question revolves around the constituents formed in iron-carbon alloys, particularly regarding ferrite and cementite. The correct answer is C) The ratio depends on the specific alloy. Ferrite (α-Fe) and cementite (Fe3C) are formed during the solidification of steel or cast iron, and their ratio depends on the carbon content and cooling rate of the alloy. As for part C of the question, the relative proportion of atoms in iron oxide could either be in the ratio of 2:3 for Fe2O3 (hematite), or in the ratio of 1:1 for FeO (wüstite), or 3:4 for Fe3O4 (magnetite).
D) The Fe and O atoms stick together in iron oxide due to ionic and covalent bonding where the balance between the positively charged iron ions (Fe2+ and Fe3+) and the negatively charged oxygen ions (O2-) creates a stable compound. E) Iron oxide is made up of metal atoms (iron) and nonmetal atoms (oxygen), thus it is a combination of these two types of atoms.