Wednesday, February 3, 2010


We have begun investigating a method of heat transfer known as convection.  The molecules of liquids and gases are not as tightly packed as those of solids.  There are spaces between the molecules.  This means that the molecules can move from place to place.

When a liquid or gas is heated:
1.  The molecules closest to the heat get hot first.  They vibrate faster.  They also move.  They move away from the heat.

2.  Cooler molecules move in and take their place.
3.  The cooler molecules are heated.  Then they move away.
4.  Other molecules move in to take their place.
5.  This happens over and over again.  Little by little, all the molecules in the gas or liquid are heated.
The first activity we did was called, "The Convection Snake".  The second activity was called, "Spot Drop" where we set up a convection current in water usling food coloring.

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