2. ◦ A change in state from a solid to a liquid occurring at a specific temperature

3. ◦ At its melting point, the particles that make up the solid are vibrating so fast that they break free from their fixed positions ( the particles gain energy)

4.  The change of state from a liquid to a solid

5. ◦ The particles of a liquid are moving so slowly that they begin to form a regular pattern. ( the particles lose energy) 

6.  The change from a liquid to a gas

7.  The particles in the liquid gain enough energy to form a gas

8.  Vaporization that takes place only on the surface of the liquid  Added energy enables some of the molecules on the surface to escape into the air

9.  Occurs when a liquid changes to a gas below the surface. You see bubbles

10. ◦ Temperature in which a liquid bubbles is called its boiling point

11.  The boiling point of a substance depends on the pressure of the air above it

12. ◦ The lower the pressure the less energy needed for the particles to escape into the air.

13. ◦ Increase elevation decrease the pressure

14. ◦ When a gas changes into a liquid ◦ Occurs when particles lose enough thermal energy to form a liquid.

15.  Occurs when the surface particles of a solid gain enough energy that they form a gas.  During sublimation, particles of a solid do not pass through a liquid state as they form a gas

16.  (eg) Dry Ice: IS solid carbon dioxide. At ordinary atmosphere pressures CO₂ cannot exist as a liquid. As the CO₂ gains thermal energy it turns into a gas. This gas cools the water vapor around it, turning it into a liquid. That’s why dry ice forms a fog around it. 