Heating and Cooling curve

Heating curve                                                                            

This is a heating curve. In the heating curve, we can see an increase in the amount of kinetic energy stored within the particle as time passes, and also a change in the state of matter, from solid to liquid to gaseous. The diagonal line represents an increase in temperature, and the horizontal line represents a change in the state of matter. The temperature doesn't increase during the time when the state of matter is changing because the heat is used to create more intermolecular space and is released, therefore keeping the temperature of the object the same.

Cooling curve

This is a cooling curve. In the cooling curve, we can see a decrease in the amount of kinetic energy stored within the particle as time passes, and also a change in the state of matter, from gaseous to liquid to solid. The diagonal (slightly curved) line represents a decrease in temperature, and the horizontal line represents a change in the state of matter. The temperature doesn't decrease during the time when the state of matter is changing because the heat is being released to lower the intermolecular space, therefore keeping the temperature of the object the same.