Heating and cooling curves

Changes of states can be explained by using the idea that particles are constantly in motion . This is called the kinetic particle theory we can explain a heating curve using ideas about the energy and motion of the particles. Heating Curve  

At point A Physical status is Solid From A to B increasing heat energy increases vibration of the solid particles so the temperature of the solid increases From B to C increasing the heat weakens the forces of attraction between particles so they begin to slide over each other . there is no temperature change because all energy supplied is used to overcome the forces between the particles instead of raising the temperature . the substance melts At C , the substance is all at liquid state.      

 Note this is the same curve as above     From C to D : increasing the energy increases the motion of the particles in the liquid so the temperature of the liquid increases. From D to E : forces of attraction between liquid particles weakens to particles start to move away from each other . there is no temperature change as the energy supplied is used to break the forces between the particles , the substance boils . From E to F : increasing the energy increases the speed of the gas particles . so the temperature increases and the gas particles are getting far away from each other.   Cooling Curve Almost opposite is happening