Chapter 3 – States of Matter

3.1 Solids, Liquids, and Gases Definite Shape Definite Volume Particles vibrate in fixed positions Particles have low kinetic energy

Liquids Variable shape (takes the shape of the container) Definite Volume Particles can move around each other Particles have medium Kinetic Energy

Gases Variable shape Variable volume (fills all space in a container) Particles move about freely Particles have high Kinetic Energy

Bose-Einstein Condensate Plasma Exists only at extremely high temperatures 99% of the matter in the UNIVERSE is plasma Stars are plasma Bose-Einstein Condensate Exists only at extremely low temperatures Groups of atoms behave as a single particle

Kinetic Theory Kinetic energy = energy an object has due to its motion The faster an object is moving; the greater its kinetic energy. Kinetic theory states that all particles of matter are in constant motion. ** View animation on visual concepts CD

3.2 The Gas Laws Pressure = the result of force distributed over an area In a closed container, gases exert pressure when the particles of the gas collide with the walls of the container.

Factors That Affect Gas Pressure Temperature – raising temp. will increase pressure if volume of gas and # of particles are kept constant Inc. in temp.  part. move faster  part. collide with walls more frequently  increased pressure

Volume – Decreasing volume of a gas causes an increase in pressure if the temp. and # of part. are constant Decrease in vol.  less space  particles collide with walls more often  inc. pressure

Number of particles – increasing the number of particles of a gas will increase pressure if temp. and volume are constant Inc. # of particles  particles collide with container more often  inc. pressure

Gas Laws Charles’ Law – volume of a gas is DIRECTLY PROPORTIONAL to temperature Note: Temperature must be in Kelvins. V1 = V2 T1 T2

Boyle’s Law – volume of a gas is INVERSELY PROPORTIONAL to pressure For Example: Increase Volume x2  Decreased pressure by ½ P1V1 = P2V2

The Combined Gas Law – relates temperature, volume and pressure of a gas. P1V1 = P2V2 T1 T2 http://videos.howstuffworks.com/science/hot-air-balloon-videos-playlist.htm#video-43

3.3 Phase Changes Phase change – reversible physical change that occurs when a substance changes from one state of matter to another Temperature of a substance DOES NOT CHANGE during a phase change. Energy is either absorbed or released during a phase change. Endothermic – energy is absorbed Exothermic – energy is released

Melting and Freezing Melting Solid changes to liquid Particles absorb energy (endothermic) Particles become less orderly

Freezing Liquid changes to solid Particles release energy (exothermic) Particles become more orderly

Vaporization and Condensation Liquid changes into a gas Particles absorb energy (endothermic) Particles become LESS orderly and more free to move 2 types of vaporization Evaporation – takes place at the surface of a liquid Boiling – occurs when a liquid is heated to its boiling point

Condensation Gas changes to a liquid Particles release or lose energy (exothermic) Particles become MORE orderly

Sublimation and Deposition Changing from a solid directly to a gas Energy is absorbed (endothermic) Deposition Changing from a gas directly to a solid Energy is released (exothermic)

Phase Change Diagram