What is the oxidation state of Br?

The bromine atom in bromine fluoride, or BrF, has an oxidation number of + 1. In bromine dioxide, or BrO2, it has an oxidation number of + 4. This is because fluorine usually has an oxidation number of - 1, and oxygen usually has an oxidation number of - 2.

Answer: - 1

Explanation: The oxidation state of Bromine is - 1. Since it is found in group 7 Halogens its oxidation is - 1 considering that it is an anion which requires 1 electron to become fully octet on its outer shell.