The figure that follows contains ball-and-stick drawings of three possible shapes of an AF4 molecule. (a) For each shape, give the electron-domain geometry on which the molecular geometry is based. iii.

Key Concepts

Electron-Domain Geometry

Electron-domain geometry refers to the spatial arrangement of all electron domains (bonding and lone pairs) around a central atom in a molecule. It helps predict the overall shape of the molecule based on the number of electron domains. For example, a central atom with four electron domains will have a tetrahedral electron-domain geometry.

Molecular Geometry

Molecular geometry describes the three-dimensional arrangement of the atoms in a molecule, which is influenced by the electron-domain geometry. While electron domains include lone pairs, molecular geometry focuses solely on the positions of the atoms. For instance, a tetrahedral electron-domain geometry can lead to different molecular geometries, such as tetrahedral or trigonal pyramidal, depending on the presence of lone pairs.

VSEPR Theory

Valence Shell Electron Pair Repulsion (VSEPR) theory is a model used to predict the shape of molecules based on the repulsion between electron pairs around a central atom. According to VSEPR, electron pairs will arrange themselves to minimize repulsion, leading to specific molecular geometries. This theory is essential for understanding how the shapes of molecules, like AF4, are determined by their electron-domain arrangements.