Answer : The stage 3 shows the liquid state of a substance.
Explanation :
In the given phase diagram,
Stage 1 : It shows the solid state of a substance.
Stage 2 : It shows the melting and freezing process of a substance. It means that when the phase changes from solid state to liquid state at constant temperature is know as melting process and when the phase changes from liquid state to solid state at constant temperature is know as freezing process.
Stage 3 : It shows the liquid state of a substance.
Stage 4 : It shows the evaporation and condensation process of a substance. It means that when the phase changes from liquid state to gaseous state at constant temperature is know as evaporation process and when the phase changes from gaseous state to liquid state at constant temperature is know as condensation process.
Stage 5 : It shows the gaseous state of a substance.
Hence, from the above information we conclude that the stage 3 shows the liquid state of a substance.
