1. Energy!

2. Energy What do you feel like when you have no energy? What do you really not want to do? –Being lazy and doing no work! Energy: The ability to do work

3. Energy Forms Potential: Stored Energy Kinetic: Energy of Motion Heat Light Nuclear Sound Electrical Chemical

4. Energy & Changes Energy is involved with any change If a change absorbs energy: –Endothermic Change If a change releases energy: –Exothermic Change =

5. Quick Quiz 1.) In an Endothermic Change, energy is ________. 2.) In an Exothermic Change, energy is ________. Answers: 1.) Absorbed 2.) Released

6. Heat and Temperature Are these the same things? NOT the same thing! –Heat is the thermal energy that is transferred –Temperature is the measure of average kinetic energy (or measurement of hot and cold)

7. Heating Curve of H 2 O

8. Heating Curves Heat of Fusion ΔH fus : –Solid to Liquid (Example: Ice Melting) –Heat Energy used to move molecules by each other Heat of Vaporization ΔH vap : –Liquid to Vapor (Example: Water Evaporating) –Heat Energy used to move molecules apart

9. Heating Curves Since Temperature is a measure of "Average Kinetic Energy", any change in temperature is ____________ energy. –Kinetic Energy Since temperature does not change during a phase change, the energy that is gained or lost is ____________ energy. –Potential Energy

10. Phase Diagrams Like a Heating Curve, but adds pressure to the equation

11. Phase Diagrams Triple Point: Where the three states of matter meet (aka equilibrium) Critical Point: At and past a certain temperature and pressure, gases are all that can exist

12. Temperature Conversion Kelvin (K) – SI Unit of Temperature Celsius ( o C) Fahrenheit ( o F)

13. Kelvin and Celsius Boiling Point of Water (at sea level) –212 o F –100 o C –373 K Freezing Point of Water –32 o F –0oC–0oC –273 K

14. Converting o C and K o C + 273 = K 15 o C = _____ K 475 K = _____ o C