The formula unit for calcium bromide is represented as CaBr₂, which indicates that it consists of one calcium ion (Ca²⁺) and two bromide ions (Br⁻). Therefore, the correct option is:
- 1 Ca²⁺ ion and 2 Br⁻ ions.
However, since this exact option is not present in your provided choices but taking into account the specific ions correctly, the closest match based on the given options would be:
- 1 Ca²+ ion and 2 Br- ions.