According to VSEPR theory, how are electron pairs arranged around a central atom?

The correct answer is that according to VSEPR (Valence Shell Electron Pair Repulsion) theory, electron pairs are arranged around a central atom as far apart as possible. This theory is based on the principle that electron pairs, whether they are bonding pairs (shared between atoms) or lone pairs (non-bonding), will repel each other due to their like charges.

To minimize this repulsion, the electron pairs will adopt arrangements that maximize the distance between them. This leads to specific molecular geometries depending on the number of electron pairs around the central atom. For example, if there are two electron pairs, the arrangement is linear; if there are three, it adopts a trigonal planar shape; and with four pairs, the shape becomes tetrahedral. All these shapes are oriented to keep the electron pairs as far apart as possible from each other, reducing the potential for repulsion between them.

This fundamental aspect of VSEPR theory is critical for predicting the geometry of molecules, which in turn informs their reactivity and properties.