What are the three types of intermolecular forces?

What are the three types of intermolecular forces?

• A. Hydrogen bonding; Dipole attraction; Dispersion forces
• B. Ionic bonding; Metallic bonding; Covalent bonding
• C. Covalent bonds; Ionic bonds; Metallic bonds
• D. London forces; Magnetic forces; Electrostatic forces

Answer: (A)

Intermolecular forces are the attractions between separate molecules. The three main types are London dispersion forces, dipole-dipole interactions, and hydrogen bonding. London dispersion forces arise from momentary fluctuations in electron distribution that create temporary dipoles; they’re present in all molecules and grow stronger with larger, more polarizable electron clouds. Dipole-dipole interactions occur in polar molecules that have permanent dipole moments; the positive end of one molecule is attracted to the negative end of another. Hydrogen bonding is a stronger form of dipole-dipole interaction that happens when hydrogen is bonded to nitrogen, oxygen, or fluorine, and the hydrogen interacts with lone pairs on a neighboring electronegative atom. This interaction has a big influence on properties like boiling points and solubility. Options that group bonds inside a molecule—ionic, metallic, or covalent bonds—don’t describe intermolecular forces, so they aren’t the right framework. Likewise, listing magnetic forces or vague electrostatic forces isn’t aligned with the standard three categories. The listed trio—dispersion, dipole-dipole, and hydrogen bonding—is the correct set to describe how molecules attract one another.

Intermolecular forces are the attractions between separate molecules. The three main types are London dispersion forces, dipole-dipole interactions, and hydrogen bonding. London dispersion forces arise from momentary fluctuations in electron distribution that create temporary dipoles; they’re present in all molecules and grow stronger with larger, more polarizable electron clouds. Dipole-dipole interactions occur in polar molecules that have permanent dipole moments; the positive end of one molecule is attracted to the negative end of another. Hydrogen bonding is a stronger form of dipole-dipole interaction that happens when hydrogen is bonded to nitrogen, oxygen, or fluorine, and the hydrogen interacts with lone pairs on a neighboring electronegative atom. This interaction has a big influence on properties like boiling points and solubility.

Options that group bonds inside a molecule—ionic, metallic, or covalent bonds—don’t describe intermolecular forces, so they aren’t the right framework. Likewise, listing magnetic forces or vague electrostatic forces isn’t aligned with the standard three categories. The listed trio—dispersion, dipole-dipole, and hydrogen bonding—is the correct set to describe how molecules attract one another.