$6\mathrm{.}1$ What is the melting point of the above substance? $q,6\mathrm{.}2$ Write down the boiling point of the above substance? $q,6\mathrm{.}3$ Which letter in the diagram represents the present of solid only? $q,6\mathrm{.}4$ Which sections of the graph show an increasing average kinetic energy of particles? $q,$