Kinetic Molecular Theory KMT Kinetic Molecular Theory

Kinetic energy = energy from motion Kinetic theory = the particles that make up matter are in constant motion Motion and temperature are directly proportional

Take shape and volume from container, can be compressed, and expand limitlessly far apart = less attraction between particles particles move quickly and randomly lots of MOTION = lots of ENERGY vapor - gas that would normally be a liquid (or solid) at room temp pressure –the force with which gas particles hit the container Gas

Liquid fixed volume, shape of container, expand when heated particles in contact, but can flow past each other closer together = more attraction particles move slower less motion = less energy Liquid

Solid Definite shape & volume particles packed tightly packed tight = very high attraction particles vibrate in a fixed position little motion = less energy ONLINE DEMO http://www.chamotlabs.com/Phases.html Solid

Energy IS NOT MATTER! Ex: light, heat, and sound Heat (energy) is added – particles move faster ENDOTHERMIC. Heat (energy) is released – particles move slower EXOTHERMIC http://mutuslab.cs.uwindsor.ca/schurko/animations/waterphases/status_water.htm

Phase changes Process of changing from one phase to another Solid Liquid Gas

Phase Changes Energy Flow causes Phase Changes: To change state particles must absorb or release energy this energy IS CONSERVED

Phase Change Graphs Show how temp increases as heat is added temperature is going up to speed particles up Kinetic Energy (KE) increases when melting or boiling (flat lines), the heat is used to break particle attractions and spread them apart Potential Energy (PE) increases

Energy must be added to cause melting or evaporation

Phase Diagrams Pressure vs temperature – shows when the different phases exist Important points on a phase diagram ‘Normal’ freezing and boiling points – pressure of 1 atm Triple point – the temp and pressure where all 3 phases co-exist Critical point – indicates the highest temp and pressure that a substance can be liquid Supercritical fluid – a substance BEYOND the critical point Has properties of a gas and a liquid

Phase Diagram of H2O