What is the distinction between glass transition (emperature and melting temperature?

Answer: The main differences between the glass transition temperature (Tg) and the melting temperature (Tm) of a material are their association with the nature of the phase transition, material properties, and thermodynamic properties. Tg occurs in amorphous materials and involves a transition from a rigid, glassy state to a more flexible, rubbery state with no sharp change in physical properties. Tm occurs in crystalline materials and involves a transition from a solid to a liquid state with a sharp change in properties like viscosity. Glass transition is a second-order phase transition (no change in enthalpy), while melting is a first-order phase transition (change in enthalpy). Both processes are reversible.