Question

how is the strength of inter particle forces related to the melting point of the substance

Answer 1

Intermolecular forces are the bonds which adjacent molecules form. There can be many types of intermolecular forces (NOTICE: these are NOT INTRAmolecular forces, i.e. Covalent or ionic!). Some types of intermolecular forces are ion:ion, ion:dipole, hydrogen bonds, dipole:dipole, induced dipole:dipole, and induced dipole:induced dipole. These have been ordered from highest strength to lowest strength. Therefore, the melting/boiling points of these would go from highest to lowest as well. This is because melting/boiling requires the disruption of intermolecular forces (to varying degrees, melting less so than boiling). To disrupt or break an intermolecular force, energy needs to be added (endothermic). Therefore, if a bond has a lot of energy (e.g. ion:ion) it takes a lot of energy to input to break, therefore the temperature of the melting/boiling point is higher than a weaker intermolecular force (e.g. dipole:dipole).

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Answer 2

The strength of inter particle substances is related to the melting point because as a substance is heated it breaks the inter particle force and there is increase in its kinetic energy and the substance starts melti