CHAPTER 3: STATES OF MATTER PHYSICAL SCIENCE
3.1 SOLIDS, LIQUIDS, AND GAS SOLID = DEFINITE SHAPE AND VOLUME LIQUID = DEFINITE VOLUME ONLY GAS = NEITHER
OTHER STATES OF MATTER 99% of matter observed in the universe exists at extremely high temperatures as plasma. We see this on earth in the form of lightning
KINETIC THEORY Kinetic energy - energy due to motion. The faster an object moves the more kinetic energy it has. Kinetic Theory states that ALL particles of matter are in constant motion.
BEHAVIOR OF GAS The particles of gas are NEVER at rest Forces of attraction are almost non-existent in gas Particles are spread farther apart and have lots of room to move
BEHAVIOR OF LIQUIDS A liquid takes shape of its container because particles can flow to new locations. The volume of a liquid is constant because forces of attraction keep particles together. Particles have room to move Rain drops are a perfect example
BEHAVIOR OF SOLIDS SOLIDS HAVE A DEFINITE SHAPE AND DEFINITE VOLUME Particles are packed in tightly and have little or no room to move….so they vibrate
PRESSURE…a review Pressure: result of force distributed over an area. SI Units: Force = Newtons = N Area = Square Meter = m2 Pressure = Pascal = Pa PRESSURE = N/M2 Pressure often expressed in kPa (kilopascals = 1000 pascals_
FACTORS AFFECTING GAS PRESSURE Collisions between particles of a gas and the walls of the container cause the pressure in a closed container of gas. Factors affecting pressure are: temperature, volume, and number of particles
TEMPERATURE IF TEMPERATURE GOES UP SO DOES PRESSURE….WHY??? WHAT KIND OF RELATIONSHIP IS THIS?
VOLUME AS VOLUME GOES DOWN PRESSURE GOES UP…WHY??? WHAT KIND OF RELATIONSHIP IS THIS?
NUMBER OF PARTICLES IF THE NUMBER OF PARTICLES GOES UP SO DOES THE PRESSURE….WHY??? WHAT KIND OF RELATIONSHIP IS THIS?
CHARLES’S LAW THE VOLUME OF A GAS IS DIRECTLY PROPORTIONATE TO ITS TEMPERATURE IN KELVIN IF THE PRESSURE AND NUMBER OF PARTICLES ARE CONSTANT…if the volume goes up, then the temperature went up. FORMULA: V1/T1 = V2/T2 TEMPERATURE MUST BE IN KELVINS
BOYLE’S LAW THE VOLUME OF A GAS IS INVERSELY PROPORTIONATE TO ITS PRESSURE IF THE TEMPERATURE AND NUMBER OF PARTICLES ARE CONSTANT….if the pressure goes up, the volume goes down (SQUEEZE) FORMULA: P1V1 = P2V2
COMBINED GAS LAW USED TO DESCRIBE THE RELATIONSHIP AMONG TEMPERATURE, PRESSURE, AND VOLUME OF A GAS WHEN THE NUMBER OF PARTICLES IS CONSTANT. CHARLES’S AND BOYLE’S LAWS COMBINED FORMULA: P1V1/T1 = P2V2/T2
CHPT 3 SEC 3: PHASE CHANGES
PHASE CHANGE CHARACTERISTICS Phase change: reversible physical change when a substance changes from one state to another. Melting, freezing, vaporization, condensation, sublimation, and deposition…six common phase changes.
PHASE CHANGES
TEMPERATURE & PHASE CHANGE SEE FIG 17 ON PAGE 85 Temperature changes up to and directly after a phase change.
ENERGY AND PHASE CHANGE ENERGY IS EITHER ABSORBED OR RELEASED DURING A PHASE CHANGE. Endothermic: a change in which energy is absorbed… cold is released…melting Heat of fusion: heat required for an object to melt Exothermic: a change in which energy is released… heat is released…freezing
MELTING AND FREEZING THE ARRANGEMENT OF WATER MOLECULES BECOMES LESS ORGANIZED AS IT MELTS AND MORE ORGANIZED AS IT FREEZES
VAPORIZATION: CHANGES FROM LIQUID TO GAS ABOVE BOILING POINT HEAT OF VAPORIZATION: HEAT ENERGY REQUIRED TO TURN LIQUID INTO A VAPOR…DIFFERENT FOR DIFFERENT SUBSTANCES EVAPORATION: TAKES PLACE ON SURFACE OF LIQUID AND OCCURS AT TEMPS BELOW BOILING POINT
CONDENSATION: CHANGE FROM GAS/VAPOR TO A LIQUID… CONDENSATION: CHANGE FROM GAS/VAPOR TO A LIQUID…..FOG ON BATHROOM MIRROR SUBLIMATION: CHANGE FROM SOLID TO GAS…. NO LIQUID PHASE..DRY ICE DEPOSITION: GAS/VAPOR TO SOLID… STILL NO LIQUID PHASE..FROST ON WINDOWS