1. Kinetic Molecular Theory
KMT
Kinetic Molecular Theory

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

3. 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

4. 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

5. Solid Definite shape & volume particles packed tightly
packed tight = very high attraction
particles vibrate in a fixed position
little motion = less energy
ONLINE DEMO
Solid

6. 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

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

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

9. 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

10. Energy must be added to cause melting or evaporation

12. 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

13. Phase Diagram of H2O