Molecule Shapes

such as linear, triangular, square planar, pyramidal, octahedral etc. The shape of a molecule affects its chemical and physical properties. For instance, some of the unique properties of water are due to the angular shape of its molecule (H₂O). The stability and the self-replicating property of DNA is due to its double-strand structure. This shows that the geometry of a molecule affects its properties significantly.

are formed due to the (non-directional) coulombic force of attraction between oppositely charged ions. Mainly, the relative ionic radii determine the structure of ionic crystals as the strength of interaction between two ions is same in all the directions.

are directional because the shared pair of electrons remain localised in a definite space between the nuclei of the two atoms. Thus, the shape of a covalent compound is determined by the number and the direction of the covalent bonds in its molecule.