Final answer:
The chemical formula of the product when sodium combines with bromine is NaBr, forming an ionic compound with a 1:1 ratio of Na+ and Br- ions.
Step-by-step explanation:
When the metallic element sodium (Na) combines with the nonmetallic element bromine (Br2), the chemical formula of the product is NaBr. Sodium and bromine react in a 1:1 ratio because sodium (Na) has an oxidation number of +1 and bromine (Br) has an oxidation number of -1 as a bromide ion (Br-). Consequently, the ionic compound that forms is composed of equal numbers of cations (Na+) and anions (Br-).
In similar reactions, such as when sodium (Na) combines with chlorine (Cl2) to form sodium chloride (NaCl), we used the diatomic nature of the halogens (Br2, Cl2) to balance the equation properly. It is also essential to remember that halogens like bromine exist as diatomic molecules. The balanced chemical equation for the reaction between sodium and bromine would be: 2Na (s) + Br2 (l) → 2NaBr (s).