Phase Changes

​From -40 degrees to 0 degrees energy is being added to water and it is still a solid all that time as the temperature continues to rise.

​As it reaches 0 degrees Celsius, the energy is now going towards breaking the intermolecular forces, change of state then takes place.

​During this time, the temperature remains constant and you have solid and liquid present until all of the solid is melted completely.

​From point B to C the ice is melting, during this time the temperature remains constant and there is a solid and liquid mixture until all the solid is melted. At that point the temperature will begin to rise until it reaches the boiling point.

​Once all the ice is melted, the temperature of the liquid water starts to rise. That takes place from point C to point D. You only have liquid water throughout those two points.

​When the temperature reaches 100 degrees celsius (boiling point) temperature remains constant and the phase change begins to take place. You'll find both liquid and gas from point D to E.