Condensed Matter Chap. 13: Day 1
Elastic collision = ideal REAL GASES STICK
Solids Orderly arrangement of particles Atoms VIBRATE & ROTATE. Do NOT translate. Have set shape and V.
Disorderly arrangement of particles Liquids They FLOW: takes the shape of container Close together: set Volume. Difficult to compress Disorderly arrangement of particles
Intermolecular Forces Force BETWEEN molecules Holds molecules together Determined by bonds (INTRAmolecular) or type of compound strong force = solid (ionic bonds) Melting points and boiling points depend on the intermolecular forces Stronger the forces the higher the temperatures (Direct)
Changing Phases Changing Position Changing Potential Energy
Heating/Cooling Curve Energy changes associated with phase changes Temperature = KINETIC Energy D Phase = D Position: due to D POTENTIAL Energy
D Phase D T D Phase D T D T
Changes of State Melting solid liquid gas Freezing
Changes of State Vaporization Condensation
condensation evaporation
Evaporation Conversion of a liquid to vapor below its boiling point. ONLY at the surface. Difference between a vapor and gas: Vapor is normally a liquid or solid at room temperature
SURFACE
Boiling Point The temperature at which the vapor pressure of the liquid equals the atmospheric pressure The entire liquid is changing state, not just the surface. Water boils at 1000C
The entire liquid is changing state, not just the surface. Boiling Point The temperature at which the vapor pressure of the liquid equals the atmospheric pressure. The entire liquid is changing state, not just the surface. Water boils at 100C
Changes of State Sublimation Deposition Vaporization Melting solid liquid gas Condensation Freezing Deposition
Sublimation solid goes directly to a gas (vapor): liquid phase does not exist.
S U B L I M A T O N EVAPORATION G G L S
DEPOSITION
STRONG INTERMOLECULAR FORCES Nonvolatile Substances High boiling points Low vapor pressure Don’t change phase easily WEAK INTERMOLECULAR FORCES *Volatile substances Low boiling points High vapor Pressure changes phase easily