1.36 explain why substances with simple molecular structures have low melting and boiling points in terms of the relatively weak forces between the molecules

1.36 •the atoms held within the molecule are held together by very strong covalent bonds, which aren't broken during changes of state 

                  •but the inter-molecular forces are very weak, reducing the melting and boiling points compared to ionic bonds

                             •this is because the molecules are easily parted from each other

                                       

       •most molecular substances are gases or liquids at room temperature 

       •molecular substances in their physical state are mushy i.e liquid, gas or a easily melted solid