Presentation on theme: "States of Matter: Kinetic Molecular Theory"— Presentation transcript:
1States of Matter: Kinetic Molecular Theory Holt McDougal Physical Science C3S1: Matter and EnergyGlencoe Science Physical Science C16S1: Kinetic Theory
2NGSSS Benchmark(s) SC912P12.11 SC912P8.1 Describe phase transitions in terms of kinetic molecular theorySC912P8.1
3Learning Objectives What makes up matter? What is the difference between a solid, a liquid, and a gas?What kind of energy do all particles of matter have?How do particles move in the four states of matter?How do particles behave at the melting and boiling points of matter?
4Characteristics of Matter Has massHas volumeMade of atomsAtoms in constant motion
5Kinetic Molecular Theory of Matter All matter is made of particles that are in constant motion“Stuff is moving all the time”
6Kinetic Theory 2The faster particles move, the higher the temperature of the substance.“Fast moving stuff is hotter than slow moving stuff.”
7Kinetic Theory 3At the same temperature, more massive particles move more slowly than less massive ones.“Big stuff is slower than small stuff at the same temperature.”
8What explains how particles in matter behave? Law of Conservation of MassLaw of Kinetic MovementKinetic Molecular TheoryNone of the above
9What is Thermal Energy? Energy ability to change/move matter Total energy of the particles in a materialTE = KE + PEIf temperature is lowered, particles will have less thermal energy
10Average Kinetic Energy Temperature avg of how fast particles are movingMolecules have kinetic energy at all temperatures (even absolute zero)
11What two things comprise thermal energy? Potential movement and Kinetic energyKinetic movement and Potential energyPotential movement and Kinetic movementPotential energy and Kinetic energy
12Common States of Matter Solid, liquid, gasDefinite something does not changeVariable something can change
13Solids Definite volume Definite shape Strong attraction keeps particles in placeParticle arrangement establishes chemical and physical properties
14Solid to Liquid: How?Melting point temp for solid to begin turning to liquidParticles slip out of ordered arrangementHeat of Fusion amt of energy needed to change a substance from a solid to a liquid at its melting point
16Liquid to Gas: How?Particles have enough energy to escape attractive forcesEvaporation particles at surface & travel awayBoiling point temp at which pressure of the vapor in the liquid = external pressure on surface of liquidHeat of vaporization amt of energy needed for liquid at its boiling point to become a gas
18How would you respond?What is the temperature at which a solid begins to turn into a liquid called?Which particles have the least kinetic energy?What do particles need in order to overcome the force of pressure and become a gas?How does the movement of particles in a liquid differ from the movement of particles in a solid?What causes a solid to have a definite volume and shape?
19Fluid: What is it?State of matter with variable shapeLiquidsGases
20PlasmaMatter made up of positively and negatively charged particles (i.e., ionized particles)NeutralConducts electricityStars, lightning bolts, neon and fluorescent tubes, auroras
21Thermal ExpansionIncrease in the size of a substance when the temperature is increased“Hot stuff moves faster and takes up more space.”
22Solid or Liquid: Which?Amorphous solid no melting point; soft over a range of temperaturesGlassPlasticLiquid Crystals maintain ordered structure from solid to liquid state
23What do you think? Describe the movement of particles in a fluid. Is plasma a fluid? Explain your answer.Why do all particles of matter have kinetic energy?Which of the three common states of matter has particles with the most kinetic energy?Why do all particle of matter have kinetic energy?What does temperature measure?
24Changes of State of Matter Holt McDougal Physical Science C3S2: Matter and Energy
25Learning ObjectivesWhat happens when a substance changes from one state of matter to another?What happens to mass and energy during physical and chemical changes?
26What Causes Matter to Change States? Change of state from one physical form to anotherCaused by transfer of energyIdentity of substance remains the same
27Adding and Removing energy Heating adds energyAdding NRG causes particles to move more quicklyRemoving NRG causes particles to move more slowly
28Temperature and Energy Adding NRG increases kinetic energy of the particlesRemoving NRG decreases kinetic energy of the particlesTemperature measure of the avg kinetic energy
29Think fast! What does “hot” mean for temperature? What will removing all kinetic energy do to a gas?
30Changes of State That Require Energy Melting from solid to liquidMelting point particles have enough nrg to break from rigid positionsMelting point can change if pressure changes
31Evaporation Change from liquid to gas Boiling evaporation at specific temp and pressureBoiling point temp at which liquid boils
32Sublimation Change from solid to gas Example: Solid CO2 –(room temp) Gas CO2
33What’s Your Answer?What are three changes of state that require energy?MeltingBoilingSubliming
34Changes of State That Release Energy Condensation from gas to liquidCondensation point temp to chg from gas to lqdCondensation often happens when gas touches cool surface (e.g., vapor touches cold glass and becomes water droplets)
35Freezing Point Freezing chg from lqd to solid Freezing point temp at which substances freezesFreezing point = Melting point = Freezing pointAdd nrg to melt; release nrg to freeze
36Do you recall? What is the condensation point? What is the melting point?What is the boiling point?What is the point?
37What Happens to Temperature During Changes of State? Temp does NOT chg during a chg of state“When a substance loses or gains energy, either its temperature change or its state changes (The) two changes do not happen at the same time.” (p. 51)
38By the Way: Helpful Links htmlmechanics/energy/heatAndTemperature/chang esOfPhase/changeOfState.html
39What Happens to Mass and Energy During Physical and Chemical Changes? Law of Conservation of MassLaw of Conservation of EnergyConserve to keep the same
40Holt McDougal Physical Science C3S3: States of MatterFluids
41Learning Objectives How do fluids exert pressure? What causes objects to float?What happens when pressure in a fluid changes?What affects the speed of a fluid?
42What Are Fluids Liquids and gases Particles can move past each other Exert pressure in all directions
43What Is PressureWith your neighbor, come up with a quick demonstration of pressure . . .Pressure amt of force exerted on a give surface area
44Is pressure a derived unit? Calculating PressureDivide force by areaPressure = Force/Area; P=F/APascal SI unit for pressureNewton SI unit for force1 Pa = 1 N/m2Is pressure a derived unit?Why/not?
45Try Calculating Pressure Given a force of 20N over 60m2, how much pressure is being exerted? Try this on your whiteboard.Write the formula: P = F / ASubstitute values: P = 20N/60m2Divide the units: P = N/m2Now, divide the quantities: 20/60= .33Assemble the answer: P = 0.33N/m2
46What Causes an Object to Float? Buoyant force upward force fluids exert on matterArchimedes’ Principle “The buoyant force of an object equals the weight of the fluid that the object displaces.”
47Do you remember . . . What is pressure? What is a Pascal? The amount of force exerted over an areaWhat is a Pascal?The SI unit for pressure; 1Pa = 1N/m2Given area and pressure, how does one determine the number of Newtons required?Since P=F/A, then F = P * A
48Will It Sink or Float? Compare weight to buoyant force why? By WeightBy DensityCompare weight to buoyant force why?Floats bouyant force > or = object’s weightSinks bouyant force < or = object’s weightCompare density of object to density of fluidFloats object is less dense than the fluidSinks object is denser than the fluidBTW, the density of water is . ..1 g/cm3
50What Happens When Pressure Changes in a Fluid? What happens when you squeeze a balloon?What happens when you squeeze a tube of toothpaste?Pascal’s principle “If the pressure in a container is increased at any point, the pressure increases at all points by the same amount.”
51Pascal’s Principle (formula) P(1) = P(2)If P = F / A, then what does F(1) / A(1) equal?F(1)/A(1) = F(2)/A(2)Remember, pressure is measured in pascals and 1Pa = 1N/M2
52Hydraulic Devices and Pascal Use liquids to transmit pressure from one point to anotherCar liftBeautician chairBarbershop
53Apply Pascal’s Principle to Solve A hydraulic lift uses Pascal’s principle to lift a 19,000N car. The area of the small pistons equals 10.5cm2 and the area of the large piston equals 400 cm2. What force must you exert on the small piston to lift the car?Write formulaSubstituteDo the math
54Properties of Fluids in Motion Fluids and areaFluid pressure and speedViscosity
55Fluids and AreaWhat happens when you put your finger over the opening for a water/garden hose?If the flow rate stays the same, fluids move faster through small areas than large areas.
56Bernoulli’s Principle Swiss Scientist from 1700 to 1782Published his discovery in 1738Blow across top of paperAs the speed of a fluid increases, the pressure exerted by the fluid decreases.
57Quiz: Write Questions and Answers How can you use density to determine if an object will float in a fluid?You put a small object into a cup of water and the displaced water weighs 235N. What is the buoyant force on the object? Explain your answer.How does a hydraulic device multiply force?A balloon filled with helium floats in the air. What does this tell you about the density of helium?How are speed and pressure of a fluid related?How do the attractions between particles in a fluid determine viscosity?
58Fluid Flow Viscosity Viscosity fluid’s resistance to flow Think about the principles of Kinetic Molecular Theory; why are some fluids more viscous than others?In general, the stronger the attraction between the particles of a fluid, the more viscous the fluid is.
60NGSSS and Learning Objective Questions SC912P Interpret the behavior of ideal gases in terms of kinetic molecular theoryWhat are some properties of gases?How do changes of pressure, temperature, or volume affect a gas?
61Physical Properties of Gases What are some physical properties of Gases?Class Notes these properties:Expand to fill their containersEasily mix with one anotherHave low densitiesCan be compressedAre mostly empty spaceExert pressure on their containers
62Gas Laws Boyle’s Law variable volume Gay-Lussac’s Law variable pressureCharles’s Law variable temperature
63Boyle’s LawWorks if temperature and amount of gas are constant or unchanged“For a certain amount of gas at a constant temperature, the volume of a gas decreases as the gas’s pressure increases. Likewise, the volume of a gas increases as the gas’s pressure decreases.”P1V1 = P2V2
64Practice Boyle’s LawGiven a balloon with a volume of 7.5L at kPa, what is the pressure of the balloon when the volume is 11.0L?Write the formula P1V1=P2V2Substitute values 7.5(100)=P2(11.0)Multiply 750=11.0(P2)Divide 750/11.0=11.0(P2)/11.0Assign correct units 68kPa
65Try Boyle’s Law, againA 300mL sample of H gas is at a pressure of KPA. If the pressure increases to kPa, what will be the final volume of the sample? Assume that temperature stays constant.Write the formulaSubstitute valuesMultiplyDivideAssign correct units
66Think About It . . .What might happen if you threw a full can of spray paint into a raging fire? remember the container is rigid, so its volume cannot increase!
67Pressure and Temperature Temperature measure of avg kinetic nrgIncrease temp particles gain kinetic nrg and bump sides of container more oftenIncrease temp pressure increases
68Gay – Lussac’s Law“When volume is constant, the pressure of a gas increases as temperature increases. Pressure decreases as temperature decreases.”Pressure and temperature = directly related.Change one = same kind of change in the other
69Charles’s Law: It’s the Kinetic Theory!!! A scientist named Jacques Charles did many experiments involving gas volumes and temperatures.“If gas and pressure are constant, the volume of gas increases as temperature increases.”V=Tk (where k is a constant pressure).
70How Can Graphs Illustrate the Gas Laws? Graphs show relationship between two factorsDirect relationship two variables change in the same directionInverse relationship variables change in opposite directionsStraight line directly proportionalCurved line variables don’t maintain ration