SOME MISCONCEPTIONS ABOUT HEAT & TEMPERATURE

Studies of hundreds of thousands of students on all continents and across multiple decades continue to show that students have great difficulty distinguishing between heat and temperature. And, text books are not the answer:

The key scientific concept of HEAT is Thermal equilibrium, the notion of the flow of heat energy and an ability to differentiate between heat and temperature.

All text books which deal with HEAT offer different explanations of the term, for example, ‘heat is energy’, ‘heat is a form of energy’, ‘heat comes from sun’, ‘heat is internal energy’, etc. These different explanations arguably simply amplify student confusion.

Another source of difficulty in understanding is the misconceived teaching about Change of state.

The thermodynamic quantities, heat and work, are not changes of state quantities - they are process quantities and they are meaningless in the one important thermodynamic state: the equilibrium state. This is one of the main sources of difficulties with these thermodynamic concepts…

• Designing Effective Physics Education Dr Derek Muller - University of Sydney PhD Thesis
• Student Misconceptions of Heat & Temperature Researchgate - A review of the literature

Studies have shown that when students challenge misconceptions by experiment and through discussion, they can quickly acquire the necessary underlying concepts that equip them to develop their understanding of thermal physics. ¹⁾

Thank you for hanging in there so far and, if you watched either video above, you are a legend already :)

Both long-term and recent Australian research have shown the relative effectiveness of conceptual change oriented instruction as opposed to the standard science instruction in heat and temperature related science topics.

Results revealed that conceptual change oriented instruction led to a significantly better acquisition of scientific concepts related to heat and temperature than the standard science instruction.

Thus, the conceptual change oriented instruction described in this study appeared to be successful in changing students many misconceptions related to fundamental ideas about heat and temperature.

It can be said that the main difference between the control and experimental group instruction is the focus on students’ misconceptions. So, if students are drawing on common misconceptions to make sense of new phenomena, the teachers can use this as a tool when designing their instruction. ²⁾

1. There are two types of heat, hot and cold (cold heat and hot heat).
2. Heat is a material substance like air or steam
3. Heat is a form of energy
4. Heat is hot, but temperature can be cold or hot
5. Some substances are naturally colder than others
6. Heat and cold are opposite and both are fluid materials
7. The temperature of an object is related to its size
8. If two liquids are mixed, temperature of the mixture is the sum of both temperatures
9. There is no difference between heat and temperature (heat and temperature are the same)
10. Temperature will change during melting or boiling
11. Heat transfer starts and does not stop at once when the temperature equalised
12. Air only cools other bodies if they are surrounded by air
13. Temperature is the amount of heat
14. If two bodies are at the same temperature they have the same energy or heat
15. Heat enters and leaves different materials with different ease
16. Different materials attract heat or retain heat differently
17. Objects at room temperature that feel cold have different temperatures
18. Objects could have a certain quantity of heat in them
19. Objects could get hotter than their surroundings
20. The temperature of water could exceed the boiling point
21. Constant heat means no heat exchange possible
22. Heat is a ‘state quantity’ (something in a body)
23. Metals attract, hold, or absorb cold
24. Conductors conduct heat more slowly than insulators
25. Insulators conduct heat fast and heat leaves so insulators don’t feel hot
26. Insulators absorb/trap heat Wool warms things
27. Heat is attracted by the cold body until heat and cold have neutralised
28. Heat is not an extensive quantity, but an intensive quantity

• Source - Review of research on Pervasive Misconceptions about heat ³⁾

Many students when asked what heat is, can not go beyond a statement “Heat is a form of energy”.

Some of them relate it to temperature saying that “Heat increases temperature”.

Some talk about heat as the energy content of the system. The students seem to equate heat with internal energy. No student mentions that heat is a form of energy in transit or shows awareness that heat may lead to external work.

In case of temperature, some students seem to equate it to its unit “degrees centigrade”. Some say that it measures the ‘heat content’ of the body. Some use a kind of ‘inverted reasoning’ to make statements such as “temperature causes change in heat” or “temperature is the unit which determines particular states of a body”.

When asked about internal energy, many students seemed to equate internal energy of a system with the total energy of the system.

Thermal equilibrium is a problem area for students. They were asked about the temperature attained by a body kept in a hot enclosure for a sufficiently long time. They seemed to say that the temperature attained depends on the material of the body or on its size. ⁴⁾