Here's why:

* Ionic compound: CuBr₂ is an ionic compound, meaning it's composed of a metal cation (Cu²⁺) and a nonmetal anion (Br⁻).

* Polar solvent: Water is a polar solvent, meaning it has a positive and negative end to its molecule.

* Solubility: Polar solvents tend to dissolve ionic compounds. However, the solubility of ionic compounds depends on factors like the strength of the ionic bonds and the hydration energy of the ions. In the case of CuBr₂, the hydration energy is not strong enough to overcome the strong ionic bonds between Cu²⁺ and Br⁻ ions.

Therefore, CuBr₂ dissolves to a small extent in water.