1. Thermal Energy Transfer
8th Grade Science
Thermal Energy Transfer

2. Create a Thermos
Your Thermos must
Be made of ONLY the materials provided
Be able to hold at least 50 mL of hot fluid
Be a group effort (all members must contribute ideas and/or labor)
Be completed within the time allotted
Each person: Draw and label a sketch of your original plan for your thermos

3. Self-assess Each person (answer in notebook under original sketch):
Did your original plan work?
If not, what modifications did you make and why?
If you had to change your plan draw a small labeled sketch of your finished product

4. Test it!
Mrs. Weaver pours 50 mL of liquid from the same equally heated container into each person’s container. Every 10 minutes measure the temperature of the liquid. Collect your data in your binder. Draw a graph under your data table representing the change in temperature for your product.

5. Display it! As a group create a poster about your project
Your poster should include:
A small sketch of your finished project
A graph displaying your data
A catchy (appropriate) name for your created thermos
At least three different colors

6. Compare it! As a group discuss: Who had the best Thermos? Why?
Leave behind two group members to present your findings to your classmates.
Two members should circulate the room collecting data to bring back to the group.
As a group discuss:
Who had the best Thermos? Why?
Who had the worst? Why?
Where did yours fall? Why?

7. Heat is the transfer of thermal energy.
Thermal energy exist when something is in motion, and when the atoms or molecules in a substance vibrate. Atoms and molecules have kinetic energy, which produces thermal energy.
The amount of thermal energy something has is the sum of the kinetic energy of all the particles.
So a bathtub of water has more thermal energy than a sink of water when the water is the same temperature in both

8. As something loses thermal energy, these vibrations slow down
As something loses thermal energy, these vibrations slow down. As something gains thermal energy these vibrations increase. If enough thermal energy is added to a substance, the vibrations may even cause a solid material to lose its form and melt, or a liquid substance to evaporate, or a gaseous substance to expand as the distance between the particles increases.

9. Heat transfers from areas of high temperatures to areas of lower temperatures
Heat transfer in a bathtub occurs form the hot water to the cooler air, to the cooler floor, to the cooler tub sides, and even to the cooler person in the water

10. Temperature is a measure of the average kinetic energy that the particles in a substance have at a particular location.
We call high average kinetic energy “hot” and low average kinetic energy “cold.”
There are many scales use to measure temperature. In the Kelvin Scale, 0 degrees Kelvin represent the absence of all kinetic energy, the absence of all molecular or atomic vibrations.
A cup or boiling water may have a higher temperature than a bathtub of warm water, but the bathtub would definitely have a higher total thermal energy.

11. Box #2 has higher temperature than Box #1 because there is more movement which equals more kinetic energy (look at the arrows)
Box # 3 and Box #4 have same temperature (same movement), but Box #4 has more thermal energy because there are more particles

12. Heat Insulator: A material that reduces the rate of heat transfer.
Heat Conductor: A material that increases the rate of heat transfer.

13. The best insulators are good because they prevent the air from moving around. Examples:
Pink or yellow fiberglass insulation used in houses
Paper pulp – paper is made of dried up hollow cells
Shredded newspaper or wood shavings

14. Heat Conduction – the transfer of energy through solids by direct contact
Some materials are better conductors than others
Example: metals conduct heat better than plastics
Thermal energy transfers through solid materials because vibrating atoms collide with each other.

15. Kinetic energy is transferred as the higher temperature atoms or molecules vibrate and collide with cooler atoms or molecules, warming them up and increasing their kinetic energy.

16. Conductors and Insulators are opposites.
Metal is a conductor not an insulator

17. So why would a metal thermos work so well
So why would a metal thermos work so well? Wouldn’t it just allow heat to transfer out of the cup?

19. Would Styrofoam be a good conductor or a good insulator? Why?

20. Homework
Find an item at home or at school that prevents the movement of thermal energy. Draw a sketch of the item and explain how it works.