So, what happened to the particle in the piston? If you watched the piston
compress, you probably saw the particle bounce faster and faster as the piston
got shorter and shorter.
Okay - so the gas molecules are bumping around faster and faster as the piston gets pushed down. But we can't really see molecules, so what does this mean?
If you had the right equipment, you could make a measurement and find out that the temperature inside the syringe gets hotter and hotter as you push on it. Temperature is really a measure of how fast molecules in something are moving around - the faster the molecules are moving, the hotter the temperature!
What happens if you heat up a gas? You add energy to all the molecules and they bounce around faster - meaning, the temperature goes up. Click on the link below to see an animation of this - you can change the temperature in this animation and watch what happens to the gas molecules.
|Now let's go back to
some of the questions from earlier in the lesson...
You might have heard the expression "Hot air rises?" Is this true? Why? Does this have anything to do with density?
The air on top of a mountain feels much cooler than the air at the bottom. Why is this? What about that saying, "Hot air rises?" - does this mean that the air on top of mountain should be warmer?
Be sure to write down any new ideas you have at this point. It might also be helpful to look back at your first answers to these questions.
So what about heat? Is it the same thing as temperature?
Before going on to the next section, write down your ideas about heat and temperature. Then try this activity and see if it gives you any new ideas.