1. States of Matter Ch. 10

2. The Nature of Gases 10-1

3. States of Matter (Review) Remember… –Solids have volume and shape; vibrating but fixed position –Liquids have volume and NO shape; slide past each other –Gases have NO volume or shape Particles are the farthest away from each other

4. Kinetic Theory (GAS) Kinetic Theory states that tiny particles of matter are in constant, random motion. –Particles are far apart, not attracted to each other –Travel in straight paths, independent of one another at high speeds (1660km/hr)! –Elastic collision = when gas particles collide no energy is lost Kinetic Energy = the energy of moving objects

5. Gas Pressure Gas Pressure = force exerted by a gas per unit of surface area of an object. Vacuum = empty space, no particles no pressure.

6. Atmospheric Pressure Atmospheric pressure (atm) = collisions of air molecules with objects. Barometer = used to measure atmospheric pressure. Pascal (Pa) = SI unit of pressure 1 atm = 101.3kPa = 760 mm Hg = 14.7 psi Ex: 253 mm Hg = ? atm 253 mm Hg x 1 atm = 0.333 atm 760mm Hg

8. Pressure vs. Elevation 1) Elevation increases, Atm Pressure decreases

9. Temperature Temperature = average kinetic energy of the particles in a material –Ex: when water is heated its particles are moving much faster than when it is cold 2) As Temperature Kinetic Energy (faster) As Temperature Kinetic Energy (slower)

10. Temperature vs. Pressure 3) Temperature increases, Pressure increases

11. The Nature of Liquids 10-2

12. Vapor Vaporization = liquid to a gas Vapor pressure = force due to gas above liquid in sealed container

13. Evaporation vs. Boiling Evaporation = occurs at surface of liquid that is NOT boiling. Boiling = vaporization throughout the liquid due to heat or pressure Boiling Point = temperature at which the vapor pressure of liquid is equal to the external (atmospheric) pressure.

14. Draw! Vapor Pressure < Atm PressureVapor Pressure > Atm Pressure AP VP AP VP

15. 4) Altitude Boiling Point ex: Boiling point in Mammoth is 95°C 5) Atm Pressure Boiling Pt ex: Boiling point in Death Valley is 105°C

16. The Nature of Solids 10-3

17. Solids Melting Point = temperature at which solid turns to liquid. Freezing Point = liquid  solid Freezing Point = Melting Point! Most have crystalline structure. Some are amorphous (lack structure); ex: glass, rubber, plastic

19. Changes of State 10-4

20. Changing State Changes of State: –Melting: S  L –Freezing: L  S –Evaporation: L  G –Condensation: G  L –Sublimation: S  G –Deposition: G  S Freezing

21. Phase Diagram Phase Diagram = gives the temperature and pressure at which a substance exists as a solid, liquid, and gas. –Triple Point = set of conditions in which all 3 phases (solid/liquid/gas) exist together.