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Lesson 4 Thermal Energy

  Virtual Lab

Phase Changes © Explore Learning


Background Information:

This lab will help you visualize what happens to the particles of water during the different phases, as well as what happens during a phase change. It will also help create your own heating curve for water.

Please note: if you scroll down while in the Gizmo you will see a list of questions. You DO NOT need to complete these questions. You are able to complete them for extra practice if you would like.

Parts of this lab will be used in 4.3 Assignment


  1. Click on the play icon to open the Gizmo. Print students can access the Gizmo from the Online Resources for Print Students section in their online course.
  2. Change the initial water temperature to –10 ˚C by using the slider on the right side of the screen or by typing in a new temperature.
  3. Click on “Micro view” at the bottom right side of the screen.
  4. Slide the heat energy slider all the way to the right.
  5. Click on the play button.
© Explore learning
D4.15 Initial settings
  1. Observe what happens to the molecules of water as they change phases and during each phase.
  2. Note what happens to the temperature as the water changes from a solid to a liquid and a liquid to a gas.
  3. Once you have watched the water change from a solid to a liquid to a gas, press pause on the simulation and switch to the “GRAPH” tab.
  4. Observe the heating curve of water. You may need to adjust the zoom to see your graph better. To do this, click the negative button on the graph. Take a screen shot or sketch the heating curve..  Save the screen shot as it will be submitted for a mark on 4.3 Assignment 
  5. Click reset and try running the simulation backward. Set the initial temperature of the water at 120 ˚C and slide the heat energy slider all the way to the left. Click play and watch what happens to the cooling curve of water. Take a screen shot or sketch the cooling curve for your notes.
  6. Please return to the top of this page and click on analysis to complete the analysis questions.
Initial Temperature (°C)
Final Temperature (°C)
Time It Took for Temperatures
to Reach Equilibrium
Aluminum beaker A
95
50
22 min 50 s
beaker B
5
50
Copper beaker A


beaker B


Steel beaker A


beaker B


Glass beaker A


beaker B



  1. What is different about the molecules of water during the solid, liquid, and gas phases?

    As the molecules move from a solid to a liquid to a gas, they get more motion and the bonds between them break. As a solid, the molecules are close together and do not move around much; they just vibrate. As a liquid, the molecules move around more. As a gas, the molecules have lots of space between them and they move around quickly.
  2. What happens to the temperature of the water as it changes phases? Why do you observe this?

    As the phase changes, the temperature stays stable. This is because the thermal energy is being used to break or create bonds, rather than being used to raise the temperature of the water.
  3. What happens to the temperature of the water once the phase change is completed? Why do you observe this?

    The temperature of the water will begin to increase again once the phase change is completed. This is because the thermal energy is no longer being used to change the bonds and so can now go toward increasing the temperature.
  4. Which of the following descriptions explains the process of water freezing?
    1. Water molecules speed up until they escape into a different phase.
    2. Water molecules slow down until they begin to become fixed in position.
    3. Water molecules are squeezed together by high pressure until they begin to stick together.
    4. As water molecules cool, their shape changes from rounded to irregular, making them more likely to link to one another.