th
7
Grade Science
11/26/12
Warm-up
• I put an ice cube on a plate on the counter at
home. Explain what causes the ice cube to
melt and draw the movement of particles and
thermal energy in a diagram of this situation.
Demonstration
•
•
•
•
Predict
Share
Observe
Explain
Objectives
• What is thermal energy?
• Use kinetic molecular model to explain
changes in the temperature of a material
What is thermal energy?
• All kinetic and potential energy of all the
particles in a sample of matter
• Random motion of molecules or atoms within
a substance
What does thermal energy depend
on?
• Depends on the number of particles in a
substance as well as the amount of energy
each particle has
• If either of these change, so does the thermal
energy
If exact same volume, which has more
thermal energy?
• The warmer substance has the greater thermal
energy
Not all particles in a sample have the
same energy!
Temperature
• The average kinetic energy of the individual
particles
• Temperature is different
Than thermal energy because
Thermal energy is the total
And temperature is the
average
Interactive
• http://preparatorychemistry.com/KMT_flash.h
tm
• http://www.biol.wwu.edu/donovan/SciEd491/
HeatTempUnit.pdf