Thermal Energy and the Transfer of Heat

Thermal Energy and the Transfer of

by MKMS Seventh Grade Science

Read through the text on the next two slides and write down notes in your notebook about what you think is the most important information.

You can used them on the graded questions that follow. ;)​

Key Concepts​: Thermal Energy and Heat Transfer

(They don't have to be word for word, but make sure these are included in your notes!)

Thermal energy is a measurement of the total amount of mechanical energy (kinetic and potential energy) of the particles in a substance or object.

Temperature is a measurement of the average kinetic energy (motion) of the particles in a substance or object.

Heat is the transfer of thermal energy from warmer to cooler objects.

Thermal energy ALWAYS moves from high to low energy (warmer to cooler) substances or objects.

​The three types of heat transfer are conduction, convection, and radiation.

​Conduction is the transfer of heat from a warmer object to a cooler object through direct contact.

​Radiation is the transfer of heat through electromagnetic rays. This is the only way that heat can travel in a vacuum (empty space). The Sun' s energy travels to Earth as radiation.

Convection is the transfer of heat through the movement of a fluid (like air or water). Heated fluids become less dense and rise away from their heat source and then as they cool they become more dense and sink back down and the cycle repeats, creating circular convection currents. This, in combination with other variables, is what causes global wind and water currents. 

Need more review?

​Watch the video linked on the next slide...

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Multiple Choice

1. What’s the difference between temperature and thermal energy?

• Temperature is the AVERAGE kinetic energy of the particles in a substance, and thermal energy is the TOTAL amount of mechanical energy (kinetic and potential) of the particles in a substance.

• Temperature is the kinetic energy of the particles in a substance, and thermal energy is the potential energy of the particles in a substance.

• Temperature is the TOTAL kinetic energy of the particles in a substance, and thermal energy is the AVERAGE amount of mechanical energy (kinetic and potential) of the particles in a substance.

• Temperature is the potential energy of the particles in a substance, and thermal energy is the kinetic energy of the particles in a substance.

Multiple Choice

2. If you have a large and a small glass juice, both at room temperature, which one has more thermal energy?

• the large glass

• the small juice

• neither - they have the same amount

Multiple Choice

4. What kind of heat transfer happens in a microwave?

• none

• conduction

• convection

• radiation

Multiple Choice

5. When you eat a popsicle, thermal energy travels between the popsicle and your mouth. What kind of heat transfer is this an example of?

• conduction

• convection

• radiation

• none

Multiple Choice

6. What is the formula to convert Celsius to Kelvin?

• Celsius = Kelvins + 273.5

• Celsius = Kelvins - 273.5

• Kelvin = Celsius - 273.5

Multiple Choice

7. Thermal energy always moves from __________________ to _______________ energy.

• low to high

• cold to hot

• high to low

Multiple Choice

8. What happens to the volume of an object as its heats up and cools down?

• It expands when it is cooled and contracts when it is heated.

• It expands when it is heated and contracts when it cooled.

• It stays the same.

Multiple Choice

Which picture shows material that is more dense?

• The picture of the left

• The picture on the right

Multiple Choice

If differences in air pressure produce winds, what can you conclude about temperature and air pressure based on the figure?

• As warm air rises, it creates an area of lower pressure, and cooler air flows in as wind
• Warm air is denser than cold air is, creating an area of high pressure the produces wind.
• Winds flow from areas of low pressure to areas high pressure when temperature is warmer
• Air pressure decreases at night because temperature is lower, producing land and sea breezes

Need more review?

​Watch the video linked on the next slide...

Open Ended

In complete sentences, compare and contrast the three types of heat transfer by describing at least one way they are all similar and one way they are each different.