energy changes

• Intermolecular force of attraction


  The force of attraction between liquid particles
• Liquids have a more ordered structure than gases
• Solids have a highly ordered structure
• Melting


  The process by which a solid is converted into a liquid
• Evaporation


  The process by which molecules on the surface of a liquid break away and undergo into the gas phase
• Evaporation


  A surface phenomenon where the molecules on the surface of a liquid break away and enter the gas phase
• In an open container, evaporation continues until all the liquid enters the gas phase
• In a closed container, the volume of liquid decreases for some time until dynamic equilibrium is established between evaporation and condensation
• Condensation


  The process by which a gas is converted into a liquid
• As temperature increases


  The rate of evaporation increases
• Liquids with stronger intermolecular forces have lower vapor pressure
• Liquids with weaker intermolecular forces have higher vapor pressure
• As surface area of a liquid increases


  The rate of evaporation increases
• Boiling


  The process by which vapor bubbles form within the liquid and rise to the surface
• Boiling point


  The temperature at which the vapor pressure of a liquid is equal to the external atmospheric pressure
• The boiling point of a liquid decreases as altitude increases due to lower air pressure