The temporary dipoles described above result in attractions known as London forces. Explain why these would be stronger between molecules of F2 than between molecules of H2.

Question

The temporary dipoles described above result in attractions known as London forces. Explain why these would be stronger between molecules of F₂ than between molecules of H₂.

Answer 1

London forces are stronger for larger molecules. This is because larger molecules have more electrons orbiting in a larger volume - this means they have a greater chance of having an uneven distribution of electrons (and hence have a dipole) than smaller molecules.

Note: this helps explain why I₂ is a solid at room temperature and F₂ is a gas.