StellarBecause mixtures and solutions are held together by intermolecular forces rather than chemical bonds, they can be separated by physical methods. However, simple filtering often does not work for solutions because dissolved particles are too small. Instead, separation methods take advantage of differences in physical properties such as boiling point or polarity. The two main methods emphasized in the curriculum are distillation and chromatography.
The key idea is that different substances in a mixture do not all behave the same way physically. If one substance boils at a lower temperature, it can be separated by heating. If one substance is more attracted to a moving solvent or a stationary material, it can be separated by chromatography. So physical separation methods work because they exploit measurable differences between the substances in the mixture rather than breaking chemical bonds.