In a bromine atom, you have the electron configuration [Ar]4s23d104p5 . The only half-filled orbitals could be one of the 4p orbitals. read more
In a bromine atom, you have the electron configuration #[Ar] 4s^2 3d^10 4p^5#. The only half-filled orbitals could be one of the #bb(4p)# orbitals. read more