Final answer:
The relationship between atoms, molecules, elements, and compounds involves atoms as the smallest unit, molecules as bonded atoms, elements as pure single atoms, and compounds as fixed ratios of different elements. Compounds are involved in chemical reactions, leading to product formation as demonstrated by the reaction of calcium metal with iron chloride to form calcium chloride and iron metal.
Step-by-step explanation:
The question deals with the relationship between atoms, molecules, elements, and compounds as well as the writing of chemical and ionic equations. An atom is the smallest unit of an element that retains the properties of that element. Molecules are two or more atoms bonded together; they can be the same element (O2) or different elements (H2O). An element is a pure substance made up of only one kind of atom. A compound is a substance made up of two or more different elements in a fixed ratio, such as sodium chloride (NaCl) or calcium chloride (CaCl2). Examples include molecular compounds like carbon tetrachloride (CCl4) and ionic compounds such as lithium bromide (LiBr).
When calcium metal reacts with iron chloride (FeCl3), a single displacement reaction occurs, resulting in calcium chloride and iron metal. In writing chemical equations, an understanding of the composition and behavior of compounds is crucial.
For instance, writing a dissociation equation for a compound like iron(III) acetate (Fe(C2H3O2)3) in water shows the split of the compound into Fe3+ and C2H3O2- ions. Similarly, creating a complete ionic equation for the reaction of FeCl2 (aq) and AgNO3 (aq) requires applying solubility rules to determine which compounds remain in ionic form and which form precipitates.