Misconceptions

Students may think that the temperature of a substance changes during phase transformation. This is not the case. Usually heating or cooling an object raises or lowers both the kinetic energy and the temperature - at the phase changes (boiling, melting, freezing, and condensation points) heating or cooling the substance changes the chemical potential energy of the substance instead of its' temperature (Giuseppe, 2011b). An idea for how to combat this misconception would be to boil water on a hotplate heated to higher than 100 degrees celsius. The heating surface should be higher than 100 degrees celsius (check with infrared thermometer) but the water inside the beaker, as measured with a conventional thermometer, only 100 degrees.

Another misconception students may have is that particles in solids don't move. While the bonds between solid molecules are stronger, they still have kinetic energy. A good way to demonstrate this is to have student volunteers model particle movement. First have them act as gas molecules. Tell the group of students to move around the classroom - they are free to run about as they please. Then have them hold hands (representing liquid) and then link arms (to represent solids).

Students may believe that a radioactive material is radioactive forever (Giuseppe, 2011b). These materials, however, decompose over time and half what is called a half life. A fun way of busting this misconception is the M&M half-life activity - it allows students to explore how a material decomposes and becomes less and less radioactive over time.