Matter and Temperature

1. Matter and Temperature Chapters: 2,3 and 14

2. Standards • SPS2. Students will explore the nature of matter, its classifications, and its system for naming types of matter • SPS2a. Calculate density when given mass and volume • SPS5. Students will compare and contrast the phases of matter as they relate to atomic and molecular motion • SPS5a. Compare and contrast the atomic/molecular motion of solids, liquids, gases and plasmas • SPS5b. Relate temperature, pressure and volume of gases to the behavior of gases

3. Classifying Matter Matter: anything with mass and volume: • Atom: smallest unit of an element • Element: cannot be broken down into anything simpler (by chemical means) ex hydrogen, oxygen, carbon…

4. Classifying Matter • Molecule: two or more different elements chemically bound; smallest unit of a compound • Compound: made up of molecules -formula ex NaCl

5. Pure Substances • Fixed composition and definite properties ex: water, salt, nitrogen, oxygen

6. Mixtures • combination of substances: -homogenous: parts are evenly distributed ex vinegar -heterogeneous: parts are not evenly distributed ex vegetables in a salad

7. Mixtures (cont’d) • Miscible: can mix ex gasoline • Immiscible: cannot mix ex oil and water

8. Physical Properties of Matter • Physical Properties: can be observed without changing the identity of the substance ex melting point, boiling point, dissolving magnetism, ability to conduct electricity

9. Physical Properties (cont’d) • mass: amount of matter in an object • volume: amount of space an object takes up • density: ratio between mass and volume -D= m/V -measured in g/cm3 or g/mL m D V

10. Chemical Properties • describes how a substance changes into another substance (cannot be reversed) ex flammability:ability to burn, reactivity: capacity to combine with another substance, rusting, effervescence (bubbling)

11. Matter and Energy Matter- anything that has mass and volume • 4 states: solids, liquids, gases, plasma Energy- ability to do work: • Potential • Kinetic

12. Kinetic Molecular Theory Kinetic Molecular Theory (KMT): • All matter is made of constantly movingparticles (atoms, molecules) • All particles have kinetic energy (KE)

13. Temperature and Kinetic Energy Temperature measure of averagekinetic energy the more KE an object has, the higher its temperature Thermal energy= total KE; depends on: particle speed- faster particles have moreKE number of particles- more particles have greaterthermal energy

14. 80ºC 80ºC 400 mL A B 200 mL Thermal Energy Quiz • Which beaker of water has more thermal energy? B - same temperature, more mass

15. States of Matter 1. solid:definite shape and volume 2. liquid:changes shape but not volume 3. gases: changes shape and volume 4. plasma: no definite shape or volume and full of moving charged particles

16. Energy and Solids Solids • low KE - particles vibrate but can’t move around • definite shape, volume: *crystalline - repeating geometric pattern *amorphous - no pattern (e.g. glass, wax)

17. Energy and Liquids Liquids • higher KE - particles can move, but are still close together • indefinite shape, not volume • flows-fluid

18. Energy and Gases Gases • high KE – particles move freely • indefinite shapeandvolume • flows- fluid

19. Energy and Plasma Plasma • very high KE- particles collide with enough energy to ionize (break into charged particles) • lacksdefinite shape or volume • can conduct electric current (unlike gases) • mostcommon state of matter

20. Changes of State Releasing Energy • Condensation- gas to liquid • Freezing- liquid to solid • Temperature is constant during all changes in state of matter (ex: If energy is added to ice, the temperature of ice will not rise until all the ice has melted)

21. Changes of State • Sublimation Evaporation Condensation Melting Freezing • substance does not change during a phase change, but the energy does.

22. Changes of State Requiring Energy • Melting Point: temperature at which a substance changes from a solid to a liquid • Boiling Point: temperature at which a substance changes from a liquid to a gas

23. Energy Transfer Methods • Conduction: when objects in direct contact are unequal in temperature • Convection: occurs in fluids (liquids or gases) -convection currents: rise and fall of fluids due to temperature differences (plate tectonics, wind) • Radiation: transfer of energy by EM waves; no physical contact

25. Energy Transfer • Heat: thermal energy that flows from a warmer material to a cooler material (energy transfer) -measured in joules (J)

26. 80ºC 10ºC A B Heat Transfer Why does A feel hot and B feel cold? • Heat flows from A to your hand = hot. • Heat flows from your hand to B = cold.

27. Energy Transfer • Conductor: material that can transfer energy easily as heat ex metals • Insulator: material that cannot transfer energy easily ex. plastic, foam, wood

28. Temperature Scales • T conversions: • Fahrenheit: water boils- 212◦ F water freezes- 32◦F • Celsius: water boils- 100◦ C water freezes- 0◦ C ◦F = 1.8C + 32.0 ◦C = F – 32.0 1.8

29. Temperature Scales (cont’d) • Kelvin: based on absolute zero (-273.15 ◦C, when molecular energy is at a minimum) - theoretically, KE = 0 at absolute zero (but particles actually never stop moving!) K = ◦C + 273.0 Tκ = Tс + 273

30. Specific Heat • Specific Heat (Cp) • amount of energy required to raise the temp. of 1 kg of material by 1 degree Kelvin • units: J/(kg·K) or J/(kg·°C) E = cmΔ E =energy c = specific heat m = mass delta T = temp. change T

31. Specific Heat Practice How much energy must be transferred as heat To 200kg of water in a bathtub to raise the water’s temperature from 25◦C to 37◦C? Given: Known: Solution: ΔT= 37◦C - 25◦C E = cmΔ T E= 4186J x 200kg x 12K ΔT= 12K kg·K m= 200kg E= 1.0 x 10⁴ kJ c= 4186 J

32. Law of Thermodynamics • First Law of Thermodynamics: total energy used in any process is conserved • Second Law of Thermodynamics: energy transferred as heat moves from higher T to a lower T - energy decreases in all energy transfers - entropy: measure of disorder within a system when left to itself

34. Heat Engines • Heat engines: convert chemical energy to mechanical energy through combustion - mechanical energy: transferred by work - internal combustion: burns fuel inside engine; always generate heat

35. Fluids • gases, liquids • Exert pressure, bouyancy, • 3 basic principles govern fluids: Archimedes’, Pascal’s, and Bernoulli’s

36. Pressure • Amount of force exerted on a given area • P = F A • SI unit = Pascal; 1P = 1N/m² • Fluids exert pressure in all directions

37. Buoyant Force • All fluids exert an upward buoyant force on matter • Due to increased pressure with increased depth

38. Archimedes’ Principle • Archimedes’ principle: buoyant force on an object in fluid is an upward force equal to the weight of the fluid that the object displaces

39. Buoyancy and Density • Objects with D = 1.00g/cm³ or less will float

40. Pascal’s Principle • Pascal’s principle: if pressure is increased at any point in a container, the pressure increases at all points by the same amount • P₁ = P₂ or F₁ = F₂ A₁ A₂

41. Pascal’s Principle Practice A hydraulic lift lifts a 19,000 N car. If the area of the small piston (A₁) equals 10.5 cm² and the area of the large piston (A₂) equals 400 cm², what force needs to be exerted on the small piston to lift the car? Given: Known: Solution: F₂ = 19,000N F₁ = F₂ F₁ = (F₂)(A₁) A₁ = 10.5 cm² A₁ A₂ A₂ A₂ = 400 cm² F₁ = (19,000N)(10.5cm²) F ₁ = ? 400cm F₁ = 500N²

42. Fluids in Motion • Move faster in smaller areas than large ones (think water through a partially blocked hose) • Viscosity: the resistance of fluids to flow

43. Bernoulli’s Principle • Fluid pressure decreases as speed increases

44. Behavior of Gases Properties: • Fill container • Mix with each other • Low density • Compressible (unlike solids or liquids, gases are mostly empty space)

45. Gas Laws Describe how the behavior of gas is affected by: • Pressure • Volume • Temperature (laws help predict the behavior of gases under certain circumstances)

46. P V Boyle’s Law • Boyle’s Law: volume and pressure of a gas are inversely related • P₁V₁ = P₂V₂ P₁ = initial pressure V₁ = initial volume P₂ = final volume V₂ = final volume

47. Boyle’s Law Practice A cylinder has a volume of 7.5 L and contains a gas at a pressure of 100 kPa. If the volume changes to 11 L, what is the final pressure? Given: Known: Solve: P₁ = 100 P P₁V₁ = P₂V₂ P₂ = P₁V₁ V₁ = 7.5 L V₂ V₂ = 11 L P₂ = (100 kPa)(7.5 L) P₂ = ? 11L P₂ = 68 kPa

48. P T Gay-Lussac’s Law • Gay-Lussac’s Law: pressure and temperature are directly related • P₁ = P₂ T₁ T₂ P₁ =initial pressure T₁ = initial temp P₂ = final pressure T₂ = final temp

49. V T Charles’ Law • Charles’ Law: volume and temperature are directly related (at constant pressure) V₁ = V₂ • V₁ = V₂ T₁ T₂ T₁ = initial temp V₁ = initial volume T₂ = final temp V₂ = final volume