Molecular Geometry: Molecular geometry refers to the actual shape or arrangement of atoms within a molecule, taking into account both bonding and non-bonding electron pairs. It is determined by the electron domain geometry but also considers lone pairs on the central atom.
Electron Pair Repulsion Theory: Also known as VSEPR theory, it explains that electron pairs around a central atom repel each other and arrange themselves as far apart as possible, leading to specific geometries.
Steric Number: The steric number is equal to the sum of bonded atoms and lone pairs surrounding an atom. It helps determine both electron domain and molecular geometries.