The molecular geometry of BBr3 (Boron Tribromide) is trigonal planar. This shape arises from the arrangement of the three bromine atoms around the central boron atom.
Boron has three valence electrons and makes three single bonds with the bromine atoms, which also have three lone pairs of electrons. According to the VSEPR (Valence Shell Electron Pair Repulsion) theory, the electron pairs will arrange themselves to minimize repulsion, leading to a planar configuration that is 120 degrees apart.
Because there are no lone pairs on the boron atom in BBr3, the shape remains trigonal planar, rather than bending or distorting due to lone pair repulsion. This symmetry allows the molecule to achieve a stable structure, as each bromine atom is evenly spaced apart, contributing to the overall low energy of the molecule.