Phase Change Questions

1. Clouds which you are likely to see while hot air ballooning are formed because gaseous water in the air cools enough to form tiny liquid droplets. Imagine that you are sitting on a water molecule which behaves like a single atom and you are floating around in the air. Describe what you would see and feel as you floated high into the atmosphere where the temperature is lower and you begin to encounter other water molecules in the process of forming a cloud.
   
   
   
   
   
   
   
   
2. When it snows, the liquid drops in clouds freeze solid. Describe on atomic level the difference between a liquid and a solid.
   
   
   
   
   
   
   
   
3. Liquid nitrogen boils at a frigid -80°C while water boils at 100°C. Which substance has stronger attractions between its atoms? Why?
   
   
   
   
   
   
   
   
4. Some cooking pans are advertised as "nonstick". Think about what you learned regarding differences in atomic attractions. What must be true about the atoms lining nonstick pans to give them the property of "non-stickiness"?
   
   
   
   
   
   
   
   
   
   
   
5. Many aerosol products (e.g. hair spray) contain a liquid under high pressure in a sealed metal contianer. On the side of these cans is a warning to keep the can away from heat due to danger of explosion. Explain why heating the can would cause an explosion. Be sure to talk about what is happening on the atomic level.