2. Chapter 2 Section 2 Notes Matter and Energy

3. Kinetic Theory of Matter:  Useful for seeing differences in the 3 common states of matter on earth: solid, liquid, and gas.

4. Kinetic Theory of Matter 3 Main Points 1.All matter is made of atoms and molecules which act like tiny particles that are always in motion. 2.The higher the temperature, the faster the particles move. 3.At the same temperature, heavier particles move slower than lighter particles.

5. States of Matter SSSSolid: particles are in a fixed position r rigid structure; no freedom to change positions P Particles are held closely together by strong attractions D Diagram:

6. Liquid  Liquid: particles are closely packed, but can still slide past each other Take the shape of their container Take the shape of their container Particles are close but not as close as a solid Particles are close but not as close as a solid Particles can move randomly and spread on their own Particles can move randomly and spread on their own Diagram: Diagram:

7. Viscosity:  Viscosity: resistance of a fluid to flow syrup is more viscous than water syrup is more viscous than water Determined by the attraction of particles: the stronger the attraction, the more viscous (thick) the liquid is. Determined by the attraction of particles: the stronger the attraction, the more viscous (thick) the liquid is.

8. Gas  Gas: particles are in a constant state of motion and rarely stick together expand to fill available spaces expand to fill available spaces  Example: scents of food or perfume Diagram: Diagram:

10. Gas  A balloon filled with helium is under pressure: Pressure: force exerted per unit area of a substance If there is too much pressure (too many helium particles) in a balloon, what happens? If there is too much pressure (too many helium particles) in a balloon, what happens? A gas under pressure will escape the container if possible. Think about an air filled balloon that you let go. A gas under pressure will escape the container if possible. Think about an air filled balloon that you let go.

11. Kinetic Theory  Using the Kinetic Theory of matter, explain why a balloon filled with helium goes flat faster than one filled with regular air.

12. Fluids  Fluids: substances that can spread Both liquids and gases can spread, so they are considered fluids. Both liquids and gases can spread, so they are considered fluids.

13. Plasma  Plasma: most common state of matter in universe: NOT on Earth Makes up 99.9 % of the universe Makes up 99.9 % of the universe Plasma is superheated gas and is a collection of free moving electrons and ions; the term came about in 1920’s to represent electrically charged particles at high energy Plasma is superheated gas and is a collection of free moving electrons and ions; the term came about in 1920’s to represent electrically charged particles at high energy

14. Plasma  Examples of plasma on earth lightning lightning fire fire

15. Energy  Energy: the ability to change or move matter Examples of energy or sources of energy: Examples of energy or sources of energy:  heat, light, spring coiling, batteries Energy must be ADDED to melt or evaporate substances Energy must be ADDED to melt or evaporate substances  Aluminum must be melted before it can be recycled  As aluminum particles gain heat, particles move faster and break away from fixed positions and become liquids: called melting

16. Energy  Energy must be RELEASED to make a gas become a liquid or solid again. When H 2 O is a gas and molecules slow down the water vapor returns to a liquid (called condensation). When molecules slow down even more, the water goes to a solid (ice). When H 2 O is a gas and molecules slow down the water vapor returns to a liquid (called condensation). When molecules slow down even more, the water goes to a solid (ice).

17. Energy  Energy relationship between solid, liquid, and gas diagram: liquidgas solid Energy ABSORBED Energy RELEASED

19. Important Note:  Changing the state of matter does NOT change the substance or mass.  Water, steam, and ice are all H 2 O: the only change is the nature of attraction between molecules

20. Phase Change Diagram: Melting Freezing Condensation Evaporation Sublimation Deposition Solid LiquidGas

21. Phase Changes  Evaporation: change of a substance from a liquid to a gas.  Condensation: change of a substance from a gas to a liquid.  Sublimation: change of a substance from a solid to a gas.  Deposition: change of a substance from a gas to a solid Example: Water vapor without becoming liquid- this is how snow forms in clouds. Example: Water vapor without becoming liquid- this is how snow forms in clouds.

22. Law of Conservation of Mass  Law of Conservation of Mass: Mass cannot be created or destroyed Example: Burning a match: consider what you start and end with. Example: Burning a match: consider what you start and end with.

23. Trivia Question  Trivia Question: If mass cannot be created or destroyed, then why do we have to replace our tires when the rubber “wears away”?

24. Law of Conservation of Energy  Law of Conservation of Energy: Energy cannot be created or destroyed Energy can be converted from one form to another. Energy can be converted from one form to another.  Example: A wristwatch: from chemical energy to mechanical energy.