Physics Chapter 7 - Kinetic Particle Model of Matter

Solid

Particles closely packed in a regular pattern; vibrate in place; strong attractive forces; Fixed shape & volume; highest density; least particle energy

Liquid

Particles slightly less packed; irregular pattern; slide past each other; weaker forces; Fixed volume, no fixed shape; medium density; more particle energy than solids

Gas

Particles far apart; irregular pattern; move freely; weak attractive forces; No fixed volume or shape; lowest density; highest particle energy

Internal Energy

Energy store made up of the total kinetic energy associated with the random motion of particles and the total potential energy between particles in the system

Relation of Temperature to Kinetic Energy

A rise in temperature of a body corresponds to an increase in the average kinetic energy of all the particles in the body

Melting

Energy absorbed; Particles gain energy to break bonds; solid → liquid

Freezing

Energy released; Particles lose energy; liquid → solid

Boiling / Evaporation

Energy absorbed; Particles gain enough energy to escape as gas

Condensation

Energy released; Gas particles lose energy; form liquid

Particle Behavior During Heating

Particles gain energy, vibrate faster, and may change state if enough energy is supplied

Particle Behavior During Cooling

Particles lose energy, move slower, and may change state (e.g., condensation, solidification)

Temperature During Change of State

Temperature remains constant while energy goes into changing the potential energy of particles (breaking/forming bonds)