Humber Admissions Practice Test

Which force accounts for the movement of electrons within an atom or molecule?

1. Dipole-dipole forces

2. Dispersion forces

3. Metallic bonding

4. VSPER theory

The correct answer is: Dispersion forces

The correct choice highlights dispersion forces, which arise from the temporary fluctuations in electron distribution around atoms and molecules. These fluctuations can induce temporary dipoles, leading to weak, short-range attractions between neighboring molecules. Although dispersion forces are generally weak compared to other intermolecular forces, they play a significant role in the overall behavior of electrons within non-polar molecules and contribute to the formation of temporary molecular interactions. While dipole-dipole forces are relevant for polar molecules, they primarily describe interactions between permanent dipoles, rather than the movement of electrons within an atom or molecule. Metallic bonding refers specifically to the strong attractions between metal atoms and the sea of delocalized electrons that allow for conductivity and malleability, but it doesn't directly account for electron movement in a broad sense. VSEPR theory is focused on predicting the geometry of molecular structures based on electron pair repulsions, rather than the forces responsible for electron movement itself. Therefore, understanding dispersion forces emphasizes the subtle interactions that influence how electrons behave within various chemical contexts.