Solids, Liquids, and Gases

1. Click on the solid button for neon.
   1. Describe how atoms of neon move in the solid phase. Also, describe how they are arranged relative to one another.
   2. Comment on spaces between atoms, speed of motion, and how one atom interacts with its neighbors.
2. Click on the liquid button for neon.
   1. Describe how atoms of neon move in the liquid phase. Also, describe how they are arranged relative to one another.
   2. Comment on spaces between atoms, speed of motion, and how one atom interacts with its neighbors.
3. Click on the gas button for neon.
   1. Describe how atoms of neon move in the gas phase. Also, describe how they are arranged relative to one another.
   2. Comment on spaces between atoms, speed of motion, and how one atom interacts with its neighbors.
4. Gases and liquids have some things in common but are very different in other ways.
   1. What are two ways gases and liquids are different?
   2. What are two ways gases and liquids are similar?
5. Atoms can interact in two ways: 1. they can hit and bounce off of one another or 2. they can hit each other and stick.
   1. Which happens more often in the gas phase?
   2. Which happens more often in the liquid phase?
6. Select neon and set the phase to solid. Add heat until the material changes completely into a gas. What happens to the speeds of the atoms as the temperature rises?
7. Why is it that gases form at higher temperatures and solids at lower temperatures? Consider both the speed at which particles move at different temperatures and their stickiness in your answer.
8. Why is it that liquids exist at a temperature in between gases and solids? Again, consider speed and stickiness of particles.
9. Describe what you would have to draw to show how particles look and act when they are in the solid phase. Use the simulator to guide you, and use the same colors, and draw a picture of the atoms of a solid here along with your description.
10. Describe what you would have to draw to show how particles look and act when they are in the liquid phase. Use the simulator to guide you, and use the same colors, and draw a picture of the atoms of a liquid here along with your description.
11. Describe what you would have to draw to show how particles look and act when they are in the gas phase. Use the simulator to guide you, and use the same colors, and draw a picture of the atoms of a gas here along with your description.

12. Change the temperature in the simulator to read in °C rather than K. Use the Solid, Liquid, and Gas buttons for each of the four substances on the simulator. What temperature is given for each phase? Fill in the table below:
    

    	Neon (Ne)	Argon (Ar)	Oxygen (O2)	Water (H2O)
    Temperature for Solid
    Temperature for Liquid
    Temperature for Gas

13. Play with the simulator a bit for each substance. Do some atoms or molecules appear to be stickier than others? If so, which ones and why do you think so?
14. Will a substance with really sticky particles have lower temperatures for the solid and liquid phase or higher temperatures? Explain.
15. Will a substance with weakly sticky particles have lower temperatures for the solid and liquid phase or higher temperatures? Explain.
16. Use the temperatures you recorded in an earlier question to rank the substances from least sticky to most sticky on a scale from 1 - 4.
    Least Sticky                              1                              2                              3                              4                              Most Sticky
17. Justify your ranking in the previous question. Why did you rank the substances in the order you did?
18. Examine solid argon compared to liquid argon using the simulator by cooling liquid argon until it freezes and heating solid argon until it melts. How does the volume the argon takes up in the container change with the phase change? Why does it change that way?
19. It is well known that water expands in volume when it freezes. Examine solid water compared to liquid water using the simulator by cooling liquid water until it freezes and heating ice until it melts. Use what you see to explain why water expands when it freezes by describing how the molecules of water act when they go from liquid to solid.