The strength of intermolecular forces of attraction varies depending on the type of molecules involved. In general, the order of increasing strength of intermolecular forces is as follows:
1. **London Dispersion Forces (Van der Waals Forces):** These are the weakest intermolecular forces and occur in all molecules. They are caused by temporary fluctuations in electron distribution, leading to temporary partial charges. London dispersion forces are stronger in larger and more polarizable molecules.
2. **Dipole-Dipole Forces:** These forces occur between polar molecules with permanent dipoles. They are stronger than London dispersion forces and result from the attraction between the positive end of one molecule and the negative end of another.
3. **Hydrogen Bonding:** This is the strongest type of intermolecular force. It occurs when hydrogen is bonded to a highly electronegative atom (such as nitrogen, oxygen, or fluorine) and is attracted to another electronegative atom in a different molecule. Hydrogen bonds are responsible for the unique properties of substances like water and ammonia.
So, hydrogen bonding generally represents the strongest intermolecular force of attraction among these three types. However, it's important to note that the actual strength of these forces can also depend on factors such as molecular size, shape, and temperature.
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