Final answer:
The equation that follows the law of conservation of mass is 4Fe + 3O₂ → 2FeO₂.
Step-by-step explanation:
The equation that follows the law of conservation of mass is:
C. 4Fe + 3O₂ → 2FeO₂
In this equation, the number of atoms of each element is equal on both sides of the equation, which satisfies the law of conservation of mass. The coefficients in the equation represent the number of moles of each substance, and they must be balanced to ensure mass is conserved.