1. Temperature and Thermal Energy
Chapter 9 Section 1
Temperature and Thermal Energy

2. Kinetic Theory of Matter
Describes the motion of the particles
Matter is composed of particles that are atoms, molecules or ions
These particles are always in random motion
Moving at different speeds in all directions
Because particles are in motion, they have kinetic energy.

3. Temperature Measures the average kinetic energy of its particles
As the movement increases, the temperature increases

4. Temperature Scales Fahrenheit Celsius Kelvin (starts at absolute zero)
F = 9/5 C + 32, to go from Celsius to Fahrenheit
Celsius
C = Kelvin – 273, to go from Kelvin to Celsius
C = 5/9 (F – 32), to go from Fahrenheit to Celsius
Kelvin (starts at absolute zero)
SI unit for temperature
K = Celsius + 273, to go from Celsius to Kelvin

5. Temperature Conversion Examples
Convert 10K to C
10K = -263C
Convert 100C to K
100C = 373K
Convert 86F to C
5/9 x (86 – 32) = 5/9 x 54 = 270/9 = 30C
Convert 10C to F
9/5 x = 90 / = = 50F

6. 9.1 Temperature Conversions: Hr_ Name__________________ Date__
Copy problems, show all work, & circle answer.
77F to C
- 40F to C
37C to F
20C to F
- 20C to F

7. Thermal Energy Sum of particle potential and kinetic energy
Particles have potential energy because their molecules exert attractive forces on each other
As particles get further apart, the potential energy increases
Thermal energy of an object changes when its temperature changes

8. Heat
Heat is the measurement of thermal energy that flows from something at a higher temperature to something at a lower temperature

9. Specific Heat
Specific Heat is the amount of thermal energy needed to raise the temperature of 1 kg of a specific material by 1 degree C
Different materials = different specific heats
On a hot day, compare sand & water temps
Specific Heat of common materials (J/kgC):
Water=4184 Ice=2110 Wood=1720 Air=1010
Asphalt=920 Glass=800 Sand=664 Iron=450

10. Measuring Specific Heat
Specific heat of a material can be measured using a calorimeter
An instrument for measuring the amount of heat released or absorbed in physical and chemical processes.

11. Change In Thermal Energy Q: Ex 1 Formula: Q = m x ΔT x C
Q = m x (Tf – Ti) x C
Q = change in thermal energy (J)
m = mass (kg)
T = Tf – Ti = change in temperature (C)
C = specific heat = J/(kg x C)
Ex: Find Q if m=20kg, T rises from 15-25C, Cwood=1700J/kgC
Q=20x(25-15)x1700
Q=20 x 10 x 1700
Q=340,000 kgCJ/kgC
Q=340,000 J

12. Thermal Energy Calculation Ex 2
Air has specific heat of 1010 J/kgC. Room temp warms from 20C to 25C. The change in thermal energy Q is 363,600 J. Find m.
Q = m(Tf-Ti)C, divide both sides by (Tf-Ti)C,
m = Q / [(Tf-Ti)C] = 363,600 / [(25-20)x1010]
m = 363,600 / (5 x 1010)=363,600 / 5050
m=72kg

13. 9.1 Thermal Energy Calculation: Hr_ Name___________________ Date__
Specific heat of water is 4184 J/kgC. How much energy is needed to heat 1 kilogram of water 5 C? Find Q.
What energy Q is needed to heat 1 kg sand from 30 to 50 C if specific heat=664 J/kgC?
An iron block has specific heat of 450 J/kgC and increases its temp 3 C when 2700 J of energy are added. What is the iron mass m?

14. 9.1 Specific Heat Analysis, Date__ Name____________________ Hr__
Copy, show all work, and circle each answer.
Convert 112 F to C.
Convert 35 C to F.
Find water thermal energy Q at 1000 kg & specific heat 4184 J/kgC if it cools by 10 C.
Find thermal energy change Q of air at 72kg & specific heat 1010 J/kgC if it heats by 5 C.

15. Chapter 9 Section 2
States of Matter

16. Five States of Matter
Solid
Liquid
Gas
Plasma
Bose-Einstein Condensate

17. Solid Solids have fixed volume and definite shape
Particles are closely packed in a fixed pattern
Particles constantly vibrating in place
Attraction between particles are strong

18. Liquid State Liquids have no definite shape but have a fixed volume.
Attractive force between particles are weaker than in a solid, but are strong enough to cause particles to cling together.
Liquid particles are free to flow and take the shape of a container.
Liquids have no definite shape but have a fixed volume.

19. Gas State Gases have no definite shape or volume
Particles are much farther apart than in a solid or liquid
Attractive forces are weak because the particles are far apart
Gas containers contain mostly empty space
Gas particles will spread indefinitely until evenly distributed
This is called Diffusion

20. Plasma State Most common state of matter in the universe.
Matter consisting of positively and negatively charged particles
Does not have a definite shape or volume
Results from collisions between particles moving at such high speeds that electrons are stripped from their atoms causing charged particles at extreme temperatures.
Examples are lightning bolts, neon and fluorescent tubes, and auroras
So plasmas do not behave like other matter.

21. Aurora Borealis

22. Northern Lights

23. Aurora

24. Bose-Einstein Condensate
Observed in a lab in 1995 at low temps.
Near absolute zero and opposite of normal solids, gas atoms are clumped so that super-atoms behave like one tiny blob of material.

25. Change Energy = Change Phases
Melting: change from solid to liquid
Heat of Fusion = energy to change from solid to liquid
Freezing: liquid to solid
Vaporization: liquid to gas (two types)
Evaporation and Boiling
Condensation: gas to liquid
Sublimation: solid to gas
Deposition: gas to solid

26. Phase Change
To produce a phase change the substance must either be heated or cooled.
When a phase change occurs, the average kinetic energy of the substance that is changing remains constant.

28. Changing States Sublimation Deposition Evaporation (multi-temp)
Surface Liquid to Gas
Boiling (specific temp)
Internal Liquid to Gas
Condensation
Gas changes to liquid
Sublimation
Solid to Gas
Deposition
Gas to Solid

29. States of Matter Simulation

30. Heating Curve of a Substance

31. 9.2 Matter States Analysis, Date__ Name____________________ Hr__
Copy and answer each in complete sentences.
Explain how forces between water molecules change when an ice cube melts.
Air pressure on a mountain is lower than air pressure at sea level. Explain how water boiling point is different at sea level.
Explain how a hot air balloon rises in cool air.

32. Transferring Thermal Energy
Chapter 9 Section 3
Transferring Thermal Energy

33. 3 Ways to Transfer Thermal Energy
Thermal Energy moves from one object to another in 3 ways:
Conduction
Convection
Radiation
Heat moves from warm objects to cooler objects
Copy this picture & terms

34. Conduction
Thermal energy that is transferred through the collision of particles is conduction.
Faster moving atoms collide with slower moving particles
As these collisions continue, energy is transferred
Particles transfer heat through collisions.
Some materials conduct heat better than others
The best thermal conductors are metals
Gases are poorer conductors than solids or liquids, which makes gases better thermal insulators.

35. Convection
Thermal energy that is transferred through a moving fluid is convection.
A fluid is a material that can change its position easily, so gas like air can be a fluid!
Liquid & gas transfer heat through movement
Particles that move faster get farther apart.
So fluids usually to expand; water is an exception
Volume increases, but mass stays the same.

36. Convection Currents
Copy this picture

37. Radiation
Thermal energy transfers by electromagnetic waves called radiation (also called electromagnetic energy)
Infrared (IR)
Ultraviolet (UV)
Radiation needs no matter to transfer energy
Radiation can be absorbed, reflected, or transmitted.

38. Thermal Insulators To prevent heat flow, use a thermal insulator.
A thermal insulator is a material that traps thermal energy (keeps cold or hot).
Best insulator is gas; worst would be metal.
Choose products that trap air or have air pockets to prevent thermal energy loss.

39. 9.3 NRG Transfer Analysis, Date__ Name____________________ Hr__
Copy and answer each in complete sentences.
Describe how a convection current occurs.
Explain why convection can’t occur in solids.
Why is ceiling air warmer than air at the floor

40. Chapter 9 Section 4
Using Thermal Energy

41. Heating Systems: Forced Air
Fuel is burned in furnace and heats air in an open system.
Fan blows heated air, quickly changing room temperature.
Cold air returns to be reheated.
Code adds fresh outside air to system.

42. Radiator Heating Radiator Systems
Closed metal container contains water
Water heated and sent through pipes as hot water or steam
Radiator gives off heat, usually located under a window
Closed system; no water or steam is lost
Usually no air movement from fans.
Heat spreads slowly through room by convection but is usually constantly on so room stays warm longer. But it usually cools off slower as well.

43. Electric Heating Electric Heating Systems
Converts electrical energy to thermal energy
Often electricity is run through a metal wire which heats up.
Warm wire is either exposed to air or placed under the floor.
Usually no air movement from fans.
Heat spreads slowly through room but is usually constantly on so room stays warm longer. But it usually cools off slower as well.

44. Active Solar Heating System
Solar collectors contain fluid that heats up outdoors from the Sun’s radiant energy.
This fluid is then pumped through the house in pipes that release the heat into each room.
The fluid is then pumped outside again to collect more heat and repeat the process.

45. Thermodynamics First Law of Thermodynamics
Increase in thermal energy of a system equals the work done on a system plus the thermal energy transferred to the system

46. Thermodynamics continued
Second Law of Thermodynamics
It is impossible for thermal energy to flow from a cool object to a warmer object unless work is done

47. Refrigerators & Air Conditioners
These heat movers transfer thermal energy from one place to another by using gas that expands to cool things off.
The gas collects unwanted heat while it condenses, removes the heat and releases it somewhere else, expands, and returns to cool things off again.

48. Heat Engine
Device that converts thermal energy into work or mechanical energy
Car Engine: Internal Combustion Engine (Bonfire = External)
Fuel burned in engine chambers
Cylinder moves a piston up and down
Only about 25% of fuel is converted into work

49. Closed vs. Open System Open System Closed System
Exposed to outside forces; items may escape
Work is done across a boundary
Closed System
Self contained and sealed so nothing escapes
No work done across a boundary and no outside work done