1. STATES OF MATTER CH 3

2. SECTION 1 Matter and Energy

3. KINETIC THEORY All matter is made of atoms/molecules (tiny particles) Particles are always in motion (higher temp = faster) @ the same temp, heavier particles move more slowly than lighter ones

4. 4 STATES Solids Particles held closely together Yet still moving (vibrating) Fixed shape & volume Fixed positions Amorphous—no particular arrangement ex: wax & rubber Crystalline—ordered arrangement ex: diamonds, ice, iron Liquids Fixed volume, change shape (take the container’s shape) Can flow/be poured b/c particles move past one another Surface tension is one property of liquids; force that allows them to form spherical drops Non-compressible (because they have a fixed volume)

5. 4 STATES CONTINUED Gases Fill all open space No fixed shape or volume Compressible because there is no fixed volume Take the shape of the container Lots of open space between particles Plasma 99% of the universe is plasma Stars, (including the sun), lightning, fire, aurora borealis, and fluorescent light Not def. shape Paritcles broken aparts (ionized: free electrons) Affected by electricity and magnetism

6. THERMAL ENERGY Energy: capacity to do work; ability to change or move matter Thermal energy : the kinetic (moving) energy of a substance The more kinetic (moving) e, the more thermal (heat) e it has Depends on the # of particles Examples: a liquid has more kinetic energy than a solid, but less than a gas But an ocean would have more thermal energy than steam from a tea kettle b/c of the total # of particles Temperature: the measure of average kinetic e; does not matter how much of the substance you have

7. ENERGY AND CHANGE OF STATE Change of state is a physical state (so then boiling and freezing are physical changes) The transfer of energy is heat Changing temp = changing state Endothermic: heat energy is needed (heat enters) Evaporation, sublimation, melting Exothermic: heat energy is released (heat exits) Condensation, freezing, deposition

8. LAWS OF MASS AND ENERGY Mass is not created or destroyed Energy is not created or destroyed

9. SECTION 2: FLUIDS Fluids : non solid state of matter; particles can move freely; gases, plasmas, liquids

10. BUOYANCY Buoyant forces: Upward force working on an object b/c of the pressure that comes with depth All fluids exert pressure in all directions Archimedes : came up with the idea that buoyancy occurs when the weight of the displaced fluid is equal to the buoyant force of an object Density also determines if an object will sink or float

11. PRESSURE AND FLUIDS Pressure = force/area Pascals (Pa): used to measure pressure Pascal’s principle: F1/A1 = F2/A2 Apllication is in hydraulic devices (brakes, lifts) that take advantge of the multiplication of forces Use liquids b/c they are non-compressible

12. VISCOSITY Resistance to flow (milkshake vs. milk being poured) Bernoulli’s principle: when the speed of a fluid increases, the pressure decreases

13. SECTION 3: GASES Properties of gases No def shape or volume Take shape of container Particles move rapidly in all directions Fluids Particle collide with each other & the walls of the container Low density b/c particles so far apart Compressible Spread easily and mix easily Mostly empty space Exert pressure on the container walls

14. GAS LAWS (3) ** (FOR FIXED AMOUNTS OF GASES) 1. Boyle’s Law: as the volume increases, the pressure decreases (and conversely, as the volume decreases, pressure builds/increases) Formula: P1 * V1 = P2 * V2 Example: forcing a plunger down forces the gas into a smaller space and builds up pressure 2. Charles’ Law: Volume increases with temp increase Volume decreases as temp decreases Ex: a balloon in cold weather shrinks

15. 3. GAY-LUSSAC’S LAW Remember: as temp increases, kinetic energy increases (particles move faster) So pressure increases as the temperature increases if the volume does not change Ex: pressurized containers (propane tanks, aerosol containers) the volume is fixed and held by the container; if it is heated, the particles begin to move more rapidly and may lead to an explosion b/c the pressure has increased

16. THE END! Know vocab Know Boyle’s Law and Pascal’s Principal and how to solve problems using them Know about each of the 4 states of matter Know the difference between exo- & endothermic Know applications of: kinetic theory, laws of conservation, Archimedes, buoyant force applications, gas laws