The Valence Shell Electron Pair Repulsion (VSEPR) model is a theory used to predict the shapes of molecules based on the repulsion between electron pairs in the valence shell of atoms. According to this model, electron pairs (whether they are bonding or non-bonding pairs) in the valence shell of an atom arrange themselves in a way that minimizes their repulsion.
In the case of boron (B) with 3 valence electrons, it forms three covalent bonds to achieve a stable configuration. The VSEPR model predicts that these three bonding electron pairs will arrange themselves in a trigonal planar geometry around the boron atom. This means that the three bonds will be spread out as far apart from each other as possible, resulting in a flat, triangular shape.
In the VSEPR model, the presence of non-bonding pairs of electrons is also considered. However, boron does not typically have any non-bonding pairs because it does not readily gain additional electrons. Therefore, the VSEPR model for boron focuses on the arrangement of the bonding electron pairs to determine its molecular geometry.