Molecular geometry refers to the three-dimensional arrangement of atoms in a molecule. This spatial structure plays a crucial role in determining how molecules interact with each other and their environment.

The shape of a molecule influences its polarity, reactivity, boiling and melting points, and how it binds to other molecules. For instance, the bent shape of the water molecule (H₂O) gives it a polar nature, enabling it to form hydrogen bonds and act as an excellent solvent. In biological systems, the lock-and-key fit between enzymes and substrates relies heavily on precise molecular geometry.

Factors such as the number of bonding and nonbonding electron pairs around a central atom (explained by the VSEPR theory) determine the final shape—whether it’s linear, trigonal planar, tetrahedral, or something more complex.

Thus, molecular geometry is not just about the shape—it’s about how that shape determines function, interaction, and reactivity in chemistry and biology.