Interactions in which oppositely charged species (ions) attract each other are called?

• A. Hydrogen bonding
• B. Dipole-dipole interactions
• C. Electrostatic interactions
• D. London dispersion forces

Answer: (C)

The key idea here is electrostatic interactions, which arise from the attraction between opposite charges. Oppositely charged ions attract each other according to Coulomb’s law—the force grows with the magnitude of the charges and falls off with distance—so this is the primary binding mechanism between ions in ionic systems.

Other forces involve neutral or partially charged species: hydrogen bonding is a specific dipole interaction involving hydrogen attached to very electronegative atoms; dipole-dipole interactions occur between polar molecules with permanent dipoles; London dispersion forces are weak, temporary attractions due to instantaneous dipoles and can occur even in nonpolar molecules.