Changes in State Phase Changes

Define freezing temperature in terms of observable and measurable characteristics. Construct and interpret heating and cooling graphs from experimental data. Predict the ranking of normal freezing temperatures of a series of compounds, and explain reasons for the ranking.

Melting or Fusion  Solid is heated (energy is absorbed).  Energy is utilized to overcome IMFs.  Particles move more freely - liquid.  Characteristic Property (melting point) (s) (l)

(l) (g) There are two types of vaporization: evaporation and boiling (characteristic property) Vaporization  Energy is absorbed to break IMFs further  Even more particle freedom.  Gases form and escape.

Evaporation: particles on the surface of the liquid have enough energy to overcome the IMFs. Boiling - bubbles forming at the bottom and rising to the top where the vapour is released.

Particles on the surface have fewer IMFs than other particles.

 Kinetic energy of the particles decreases as it cools.  Particles slow down, IMFs take hold.  Energy released to surroundings. (g) (l) Condensation

(l) (s)  Particles slow down even more.  IMFs increase and hold stronger.  Energy is lost to surroundings.  Particles arrange into the organized patterns. Freezing or Solidification

Sublimation Deposition (s) (g) (g) (s)

decrease particle motion increase Kinetic Energy increase IMFs decrease IMFs decrease Kinetic Energy increase particle motion