Molecular structures refer to the arrangement of atoms within a molecule, which is the smallest unit of a chemical compound. These structures determine the molecule's properties and behavior. Atoms are held together by chemical bonds, such as covalent or ionic bonds, forming various shapes and configurations. Understanding molecular structures is essential in fields like chemistry, biochemistry, and materials science. Different arrangements can lead to different substances, such as water (H₂O) having a bent shape, while carbon dioxide (CO₂) is linear. These differences influence how molecules interact with each other and their environment.