- Temperature: average kinetic energy of a substance
○ Reflects random motions of particles
○ A change in temperature indicates an energy change 
- Heat: involves the transfer of energy between two objects due to a temperature difference
○ Heat flows from hot (higher KE) to cold (lower KE)
○ When two objects at different temperatures are in contact, they will eventually reach the same intermediate temperature/thermal equilibrium:
particles will have the same avg KE & speed/velocity
■ Energy will be transferred from the more energetic particles to the less energetic
- Decrease temperature = decrease avg KE of particles = decrease avg speed/velocity of particles