Name _________________________________________________________
Block __________________________________________________________
Date ___________________________________________________________
In-Class Activity—Atoms in Motion app using the iPad
Directions:
This app simulates the motion/movement of gas particles. You will be manipulating the conditions of the gas particles
and making observations, which you will be recording below. Complete sentences are NOT necessary, but bullet points
are fine.
1.
Press the white square at the top (next to Xe) in order to clear the page.
2. Click on He (top left) ten times. You should see 10 red atoms moving around within the white space after doing
this. Each atom represents a mole of Helium atoms, so you’ll notice that n = 10, meaning, 10 moles.
3. How would you describe the motion of these gas particles?
4. Watch the particles move. What do you notice about the pressure as you observe the particles? How then is
pressure created?
5. Are all of the particles moving at the same speed?
6. What is currently the temperature of your container? (Temperature is T, not t.) Please record this in Kelvin.
You can adjust the temperature units by clicking on the temperature value itself.
7. To increase the temperature, trace a line from the bottom of the screen going upward. What is your new
temperature? How did this change affect the movement of the particles?
8. When you increased the temperature, what happened to your pressure values in general?
9. In conclusion, as temperature increases, the pressure _________________________________.
10. To decrease the temperature down to 1 K, trace a line from the top of the screen going downward until you get
to that temperature. How does this change affect the movement of the particles?
11. Next, increase your temperature back to the 300’s or so. Zoom in on the particles on your screen. Doing this
decreases the volume of the container. What has happened to your pressure?
12. In conclusion, as the volume decreases, the pressure ____________________________________.
13. Add ten moles (ten clicks) of Xe. How would you describe the Xe particles in terms of…
a. Size?
b. Speed?
c. Level of attraction between the particles?
“The 3 Laws”
1.
Boyles’ Law: P1V1 = P2V2
As the volume increases, the pressure _____________________________________ at constant temperature.
(Make the volume smaller in your container and see what happens to the pressure. Make the volume larger in your
container and see what happens to the pressure.)
2.
Gay Lussac’s Law = P1/T1 = P2/T2
As the temperature increases, the pressure _________________________________ at constant volume.
(Make the temperature increase in your container and see what happens to the pressure. Make the temperature
decrease in your container and see what happens to the pressure.)
3. Charles’ Law = V1/T1 = V2/T2
As the temperature increases, the volume ___________________________________ at constant pressure.
(This one is more difficult to get the app to do. What you have to do is increase the temperature first. You’ll notice a
change in the pressure as a result, so the only way to get the pressure back to where it was is to adjust the volume. It
might take a couple tries to do this, but you should observe what happens.)
4.
Which of the three laws illustrate(s) a proportional relationship? Which of the three laws illustrate(s) an
inversely proportional relationship?
5.
The variables that we use when discussing the nature of gases are the following. What other relationships
between variables can you see using the app? Make at least two observations not otherwise listed here. We
will discuss them as a class at the end.
Moles (number of particles, n)
Pressure (P)
Temperature (T)
Volume (V)
Kinetic Energy (1/2 x mass x velocity2)
Mass of particles
Speed of particles
Level of attraction between particles