Induced dipoles result in Van der Waals' forces and permanent dipoles in hydrogen bonds, right? But how do you know is a compound has formed hydrogen bonds or Van der Waals' forces? For example, HF forms hydrogen bonds while HCl forms Van der Waals' forces and not hydrogen bonds. But in HCl, H is delta positive and Cl is delta negative, so shouldn't it form hydrogen bonds? But then when do Van der Waals' forces form? Thanks.