Final answer:
Electron-pair geometry is used to determine the preferred arrangement of electrons, and if polar covalent bonds don't cancel, the molecule is polar. Resonance occurs with multiple possible structures, and lone pair repulsion can cause a bent shape. Dipole moments relate to molecular polarity and intermolecular bonding, while ionic compounds' complete electron transfer makes them inherently polar.
Step-by-step explanation:
The preferred arrangement of electrons in a molecular structure can be determined by calculating the electron-pair geometry of each atom in the molecule. If the dipole moments from polar covalent bonds don't cancel, then the molecule will be polar. When a molecule can have multiple structures with electron pairs in different positions, the molecule has resonance. Repulsion between lone pairs of electrons and electrons in covalent bonds causes some molecules to have a bent shape.
The relationship between the polarity of a molecule, its dipole moment, and intermolecular bonding is in how the polar covalent bonds within the molecule do not cancel out. This results in an overall separation of charge, creating a dipole moment that enables the molecule to interact with electric fields, which directly impacts the intermolecular forces such as hydrogen bonding, dipole-dipole, and London dispersion forces. Ionic compounds are always polar because they consist of ions which have a complete transfer of electrons from one atom to another, leading to a permanent separation of charge.