| A | B |
|---|
| kinetic theory | explanation of how particles behave |
| 3 assumptions of kinetic theory | 1. all matter is composed of small particles 2. particles are in constant, random motion, 3. particles are colliding with one another and with the walls of their container |
| thermal energy | total energy of material's particles, including kinetic and potential energy |
| temperature | average kinetic energy of particles in a substance (reflects how fast particles are moving) |
| states of matter | solid, liquid, gas, plasma |
| melting point | temperature at which a solid begins to liquefy |
| heat of fusion | amount of energy required to change a substance from the solid to the liquid phase |
| solid state | particles are closely packed together and strongly attracted to each other |
| liquid state | particles have more kinetic energy than in solid phase, enough to partially overcome the attractive forces holding them in place, so particles can slide past one another |
| gas state | particles have enough kinetic energy to overcome the attractive forces between them, so they can expand or contract to fill the container they are in; have no definite shape or volume |
| vaporization | process in which particles are moving fast enough to escape the attractive forces of other particles and enter the gas state; can occur through evaporation or boiling |
| boiling point | temperature at which the pressure of the vapor within a liquid = the expernal pressure ating on the surface of the liquid |
| heat of vaporization | amount of energy needed for a liquid at its boiling point to become a gas |
| diffusion | spreading of particles throughout a given volume until they are uniformly distributed |
| heating curve of a liquid | graph that shows the temperature change of a liquid as thermal energy (heat) is added |
| plasma state | matter consisting of positively and negatively charged particles; exists where temperatures are very high and where electrons have been stripped off the atoms and are moving freely in the plasma; the most common state of matter in the universe; examples: stars, lightning bolts, neon lights, flourescent tubes, auroras |
| thermal expansion | an increase in the size of a substance when the temperature is increased. |
| special property of water in solid form | because water molecules line up according to positively and negatively charged components, empty spaces occur in the solid structure, making ice larger and less dense than liquid water, unlike other substances |
| amorphous solids | solids that do not have a definite temperature at which they change from a solid to a liquid; lack a highly ordered structure: particles for long chain-like structures that jumble and twist; examples: glass, plastic |
| liquid crystals | in melting phase, liquid crystals flow but do not lose an ordered arrangement completely; examples: liquid displays in calculators, digital watches, clocks |
| buoyancy | ability of a fluid (liquid or gas) to exert an upward force on an object immersed in it |
| buoyant force | supporting force exerted on an object; if buoyant force of fluid = weight of the object, object will float; if buoyant force of fluid is less than weight of object, object sinks |
| Archimedes' Principle | the buoyant force on an object = weight of the fluid displaced by the object |
| density | mass/unit volume. Object will float if its density is less than that of the fluid in which it is placed |
| pressure | force/unit of area P=F/A |
| Pascal's Principle | the pressure applied to a fluid is transmitted throughout that fluid |
| Bernoulli's Principle | as the velocity of a fluid increases, the pressure exerted by the fluid decreases (example: plane flight) |
| viscosity | resistance to flow by a fluid. Low viscosity = easy flow; high viscosity = slow flow; viscosity decreases as temperature increases |
| gas pressure | result of moving particles colliding with the inside walls of a container; P = F/area |
| SI unit of pressure | pascal (Pa); 1 Pa = 1 Newton/square meter |
| Boyle's Law | if you decrease the volume of a container while holding temperature constant, the pressure of the gas will increase; conversely, if you decrease the pressure, the volume will increase. |
| Charles' Law | at a constant pressure, the volume of a gas increases as temperature increases; if you decrease the temperature, the volume will decrease |
