Final answer:
The chemical reaction Br2 + 2Na → 2NaBr is best represented by an ionic model because it shows the transfer of electrons to form ions with oxidation numbers of +1 and -1 for sodium and bromide, respectively.
Step-by-step explanation:
The chemical reaction Br2 + 2Na → 2NaBr is best represented by an ionic model. This is because the reaction involves the transfer of electrons from sodium (Na) atoms to bromine (Br2) molecules, forming sodium ions (Na+) and bromide ions (Br−). The ionic model is suitable for representing the ionic product where sodium ions have an oxidation number of +1 and bromide ions have an oxidation number of -1. Other models like the ball-and-stick model are useful for visual representations, showing how atoms are connected and their three-dimensional arrangement, but the ionic model specifically highlights the ionic nature of the compounds formed.