Final answer:
The bond between bromine and fluorine in bromine trifluoride (BrF3) is a covalent bond formed by electron sharing to achieve a stable octet configuration.
Step-by-step explanation:
The bond between bromine (Br) and fluorine (F) in bromine trifluoride (BrF3) is a covalent bond. This type of bond is formed when atoms share electrons in order to obtain a stable electron configuration, which usually means achieving a noble gas electron configuration in accordance with the octet rule. In this case, fluorine, which is the element with the highest electronegativity, shares one electron with bromine to form a covalent bond. Each bromine atom forms three such bonds with three fluorine atoms to complete its octet and produce BrF3.