1. Chapter 9
Heat

2. Heat form of energy from the motion of particles
Lesson 1: What is Heat?
Heat form of energy from the motion of particles
Heat always flows from warmer to cooler
Machines change heat energy into mechanical energy

3. The sun is earth’s most important heat source
Lesson 1 Heat Sources
The sun is earth’s most important heat source
Heat source place from which heat comes
The other types of energy can produce heat energy

4. Examples: Rubbing your hands changes mechanical to heat
Lesson 1 cont.
Examples:
Rubbing your hands changes mechanical to heat
Burning fuel changes chemical to heat
A toaster changes electric to heat

5. Review
In a solid particles are closely packed and move little
In a liquid particles are slightly farther apart and move a little more
In a gas particles can move anywhere in the space

6. Lesson 2: Heat Affects Matter
Adding heat: particles move faster and farther apart
Liquid to gas evaporation
Solid to liquid melting
Solid to gas sublimation

8. Taking heat away: particles move less and closely packed
Lesson 2 cont.
Taking heat away: particles move less and closely packed
Gas to liquid condensation
Liquid to solid freezing
Gas to solid deposition

9. Lesson 2: Expansion/Contraction
Expand fill more space
Gases = most
Solids = less
Contract fill less space
Exception:
Water contracts until 4° then expands until 0°

10. Temperature measure how fast particles are moving
Lesson 3: Temperature
Temperature measure how fast particles are moving
Faster particles = higher temp.
Thermometer device used to measure temperature

12. Fahrenheit To Celsius: 5/9 * (Fahrenheit - 32)
Fahrenheit & Celsius
Fahrenheit To Celsius: 5/9 * (Fahrenheit - 32)
Celsius To Fahrenheit: (1.8 * Celsius) + 32

13. Celsius To Kelvin: Celsius + 273
Celsius & Kelvin
Celsius To Kelvin: Celsius + 273
Kelvin To Celsius : Kelvin - 273

14. Fahrenheit To Kelvin: (5/9 * (Fahrenheit - 32) + 273 )
Fahrenheit & Kelvin
Fahrenheit To Kelvin: (5/9 * (Fahrenheit - 32) )
Kelvin To Fahrenheit: ((Kelvin - 273) * 1.8 ) + 32

15. Lesson 3: Freezing Point/Melting Point
Freezing point temperature at which liquid changes to solid
Melting Point temp. at which solid changes to liquid
Water’s freezing/melting points 32°F or 0°C

16. Boiling point temp. at which liquid changes to gas
Lesson 3: Boiling Point
Boiling point temp. at which liquid changes to gas
Water’s boiling point is 212°F or 100°C

17. Lesson 3: changing freezing/boiling point
To change the freezing pt. of H2O add antifreeze (it has alcohol)
Compounds of Na & Ca are used on icy roads to keep H2O from freezing

18. Lesson 4: Measuring Heat
Temperature avg. kinetic energy
Heat total kinetic energy
Heat depends on temp. & amount of matter (mass)

19. Lesson 4: heat vs. temp.
2 objects same temp. but different masses  the 1 w/ more mass = more heat
2 objects diff temp & diff mass  the 1 w/ more mass = more heat even if temp

20. A candle flame and a bonfire  bonfire has more heat
Lesson 4 cont.
A candle flame and a bonfire  bonfire has more heat
An cup of hot cocoa and a frozen pond  frozen pond has more heat because it has more mass even though it is colder

21. Lesson 4: Measuring Heat
Calorie unit of heat
Calorie the amt of heat needed to raise 1 gram of water 1°C
Heat = ∆ temp x mass
calories = mass H2O × ΔH2O temp. × 1.0 cal /g/°C

22. Simple Calorimeters

23. Lesson 4: endothermic vs. exothermic
Endothermic absorbing heat leaving the surroundings cooler
Endothermic requires kinetic energy

24. Exothermic giving off heat leaving the surroundings warmer
Exothermic kinetic energy is released

25. Lesson 5: How Does Heat Travel?
Energy always goes from warmer to cooler
There are 3 ways heat can travel:
Radiation
Conduction
Convection

26. We get sun’s heat through radiation
Radiation movement of heat through a vacuum
Vacuum space with no matter

28. Conduction movement of heat from one molecule to another
Conductor heat travels through easily
Insulator does not conduct heat easily

30. Convection
Convection movement of heat where warm liquids or gases rise and cool liquids or gases sink

32. Dark colors absorb heat
Light colors reflect heat