Compounds can be represented as either chemical formulas or as molecular models. An empirical formula shows the simplest whole number ratio of atoms in the compound. On the other hand, a molecular compound gives the actual number of atoms of each element in a molecule of a compound. A structural formula uses lines to represent covalent bonds and shows how atoms in a molecule are connected or bonded to each other. Molecular models are more accurate. Ball-and-stick models show the geometry of the compound by representing atoms as balls and bonds as sticks. Finally, a space-filling molecular model gives a sense of the relative sizes of the atoms and how they merge together.
Work Step by Step
The type of formula or model you use depends on how much you know about the compound or on how much information that you want to communicate. Select a representation based on the application and what you already know.