Answer Key for Understanding Molecule Polarity and Bond Types

To determine whether a compound exhibits symmetry or dipole moments, focus on its atomic arrangement and electron distribution. When atoms in a compound have similar electronegativity, the resulting bond will likely be nonpolar. However, if the atoms differ significantly in their electronegativity, the electrons will be pulled towards the more electronegative atom, creating a dipole.

Consider the geometry of the molecule. If it has an asymmetrical shape, the molecule may have a net dipole moment. For example, even if individual bonds are polar, a symmetrical structure, like in carbon dioxide, cancels out the dipoles. Conversely, water’s bent shape allows for an overall dipole, giving it unique properties such as a high boiling point.

It’s also important to examine lone pairs of electrons on the central atom. These can affect the distribution of charge and influence whether a compound is polar. A central atom with lone pairs will usually result in a molecule that has a net dipole moment, as seen in ammonia.