Answer :
1. The substance is in the gas phase only in region 5.
2. The substance is in both the liquid and the solid phase in region 2.
3. The substance is in only the liquid phase in region 3.
4. The melting point is the temperature at region 2.
5. The boiling point is the temperature at region 4.
Explanation :
Melting or fusion : It is a type of process in which the phase changes from solid state to liquid state at constant temperature.
Freezing : It is a type of process in which the phase changes from liquid state to solid state at constant temperature.
Evaporation : It is a type of process in which the phase changes from liquid state to gaseous state at constant temperature.
Condensation : It is a type of process in which the phase changes from gaseous state to liquid state at constant temperature.
Sublimation : It is a type of process in which the phase changes from solid state to gaseous state without passing through the liquid state at constant temperature.
Deposition : It is a type of process in which the phase changes from gaseous state to solid state without passing through the liquid state at constant temperature.
