Here's why:

* Electronegativity: Carbon and bromine have a significant difference in electronegativity. Bromine is more electronegative than carbon, meaning it has a stronger pull on shared electrons.

* Sharing of electrons: Instead of one atom completely taking an electron from the other (ionic bond), they share electrons to achieve a stable outer electron configuration.

* Polar covalent bond: The bond between carbon and bromine is considered a polar covalent bond because the electrons are not shared equally. The bromine atom attracts the shared electrons more strongly, resulting in a slight negative charge on the bromine and a slight positive charge on the carbon.