Misconceptions: Heat and Temperature
Posted by David Wetzel
Heat and Temperature
Students have many misconceptions about science.These misunderstandings are typically held tight by students, because they are commonly misused by parents, siblings, relatives, movies, and their favorite television shows.
Student Misconceptions
Here are common misconceptions students hold related to heat and temperature.
- Heat rises
- Atoms get bigger when you heat them up
- Temperature and heat are the same thing
- Sweat cools you off in the same way as pouring cold water on you
- An object at 0 degrees has no heat
- When you touch a cold object, it transfers some of its coldness to you
- All ice is “0″ degrees Celsius
Facts
The following facts help correct these misconceptions:
- Heat does not rise. Heat cannot rise. Heat is not even a thing that could be seen even if it could rise. Heat is a form of energy.
- Atoms do not get bigger when they heat up, they only spread further apart when heated.
- Temperature and heat are not the same thing. An object can have high temperature and very little heat. An object can also have very low temperature and a lot of heat. Temperature is simply how fast molecules are moving in an object like books on a table. Heat is a form of energy that depends on the temperature as well as the type of molecule, and how many molecules in the object. Temperature is measured with a thermometer. Heat cannot be measured directly.
- Many students believe that sweat cools you down because water is cool. But sweat comes out at exactly the same temperature as your skin, maybe even a little hotter. It is not cool. So, how does it cool you then? It cools through evaporation.
- An object at 0 degrees Celsius or 0 degrees Fahrenheit does have heat. An object at 0 degrees Kelvin would not. There is one caveat, though . . . Although scientists have been very close to absolute zero, they have never reached it. It is not possible to have a temperature below 0 Kelvin so having negative heat is not possible. So it is accurate to say that everything on Earth and likely everything in the universe contains heat because everything has a temperature greater than 0 degrees Kelvin.
- Many students also believe that when they touch something cold, coldness is transferred from the cold object to their body. There is no such thing as cold. An object feels cold because it has less heat than you. The sensation of cold is the feeling that we get when heat leaves our body to enter an object with lower temperature. It is not coldness leaving the object and entering you, it is heat leaving you and entering the object.
- Many students believe that because the freezing point of water is 0 degrees C that all ice is at that temperature. But 0 degrees C is simply the maximum possible temperature for ice under normal conditions. If your freezer is set to -4 degrees C, then the ice cubes will be -4 degrees C. If it is -24 degrees C in Siberia, then the snow and ice there are at -24 degrees C.
Resource
Students Misconceptions in Science
