|The classic "Ball & Ring" demo!|
|Now it's contracting!|
|A real nice sketch of the Ball & Ring demo showing the expansion and contraction of a solid.|
|A very good write-up of the Ball & Ring demo.|
The students were able to clearly see that matter expands when heated and ccontracts when cooled. When heat energy is added to matter the molecules move faster causing the substance to get bigger, or expand. When heat energy is taken away, or cooled, the molecules slow down causing the substance to contract.
The students also observed that this meant that the volume of the substance increased when heated and decreased hen cooled. Some students were able to make the connection that heating or cooling a substance could change its density.
|The "Mood Ball" activity showing that liquid expands when heated and contracts when cooled.|
|Hard at work!|
|Another fine sketch of the days activity!|
|A very good write-up of the days activity.|
|Heated air expands.|
|A very nice sketch of the "Balloon on a Flask" activity showing the expansion and contraction of a gas (air) due to heating/cooling.|