Name: _________________________________________
Period: ____
Phases of Matter Simulation
On Earth matter commonly exists in three phases: solid, liquid, and gas. These phase changes occur
when energy is added or removed from a substance, causing it to take on new properties.
Simulation:
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URL: https://phet.colorado.edu/en/simulation/legacy/states-of-matter-basics
Search: “PhET States of Matter basics”
Neon Instructions:
1) On opening the simulation you will see a container with neon atoms in it. What phase of matter
is the neon in?
2) What is the temperature in the container?
3) Is this warm or cold relative to the temperature in this room?
4) Cool the neon by holding the bar to “Cool” and watch the temperature drop. What changes
about the neon atoms when you do this?
5) Keep holding the slider down to “Cool” until the temperature hits 0 K. What happened to the
atoms in the simulation?
6) Is it possible to reach this temperature in real life?
7) Click the “Reset All” button in the bottom left. Now hold the slider up to “Heat.” Hold it until
the temperature is 26 K. What happens to the neon?
8) What phase is the neon in now?
9) Does being in a different phase change what types of atoms you have in the container?
Water Instructions:
10) Go to the upper right of the simulation and change it from neon atoms to water molecules.
What temperature is the container now?
11) Go to the right side and click on the “Liquid” button for Change State. Watch and you will notice
that occasionally a water molecule breaks off and floats around on its own. Increase the
temperature to about 400 K. Do these “loners” occur more or less frequently?
(FYI: What you are seeing in #11 is evaporation. It isn’t actually boiling because the majority of
the molecules are still in liquid phase, but some of the molecules get extra energy and break
away as a gas. This is how water can evaporate even though it isn’t 100º C outside.)
Comparison Instructions:
12) Hit Reset All again. While leaving the element on neon, adjust it so that it is the same
temperature that you had in #10 (this will take a minute). Is neon in the same phase that water
was at the same temperature?
13) Reset again. Try to estimate the temperature at which neon turned from a liquid to a gas by
holding the Heat up and watching the behavior of the atoms.
14) Set the Atoms & Molecules to water. Using the same method as #13, estimate when water
changes from a liquid to a gas.
15) Comparing your answers in #13 and #14, which substance boils at a higher temperature?
Extra Credit:
16) Go to the Phase Changes tab at the top of the simulation. Heat the neon until it is a gas. What
does the Pressure and Temperature read?
17) Click on the handle and push the top of the container down. What happens to the pressure and
temperature?
18) If you keep pressing down, what happens eventually?