Which theory states that pairs of electrons in a molecule arrange themselves to be as far apart from each other as possible?

The theory that states that pairs of electrons in a molecule arrange themselves to be as far apart from each other as possible is the Valence Shell Electron Pair Repulsion (VSEPR) theory. This theory is based on the principle that the shape of a molecule is determined by the repulsion between electron pairs surrounding the central atom. Electrons, being negatively charged, repel each other; therefore, they will orient themselves in a way that minimizes this repulsion, resulting in specific molecular geometries.

VSEPR theory allows chemists to predict the three-dimensional shape of a molecule by considering the number of bonding and non-bonding electron pairs around the central atom. This leads to various predicted shapes, such as linear, trigonal planar, tetrahedral, trigonal bipyramidal, and octahedral, depending on how many electron pairs are present and their configuration.

The other theories mentioned provide different insights into chemical bonding and molecular structure but do not specifically address the spatial arrangement of electron pairs in the same way that VSEPR theory does. For example, molecular orbital theory focuses on the mixing of atomic orbitals to form molecular orbitals but not directly on electron pair repulsion.