- Line up in four rows of four people each. (If you have more, line up in as near the same number of rows and people in each row as you can, but it doesn’t have to be exact.)
- Each person should tie themselves to the person in front, behind, and on either side with a 1 meter piece of string. (Only those in the middle will be tied to four other people. The ones on the outside will only be tied to two or three.)
- Now pretend that your group is an ice cube, and each of you is a single water molecule in that ice cube.
- Move in as close as you can to one another and remain as still as possible. At this point there is no heat at all in the ice cube. The molecules are not moving.
- Next, pretend that you are being heated. This causes you to vibrate, so you should begin to move back and forth and side to side, but be careful not to break any of the strings. As you begin to move, you will notice that you are moving away from one another and the “ice cube” is expanding.
- More heat is being added, so you should begin to move faster. At some point, the strings will begin to break. Now you can move around, but you should hold two other people’s hands and stay within arm’s length of each other. As you move, you may change the hands you are holding. The “ice cube” has now melted, and you are water in the liquid state. Your attraction for each other as molecules has weakened with the breaking of the strings, but you hands represent the attraction the molecules in a liquid still have for each other.
- Even more heat is now being added, so you should begin to move even faster. You will soon be unable to hold onto anyone else’s hand, and you will begin moving apart. As you keep moving randomly, you will actually move farther and farther apart. Enough heat has now been added to cause the water to boil and evaporate.
Conclusion:
The molecules move in solids, liquids and gases when they are heated. When the molecules are not moving at all, there is no heat present. As heat was added, the molecules (you) moved faster and faster. When there was enough heat to cause you to melt, the heat energy overcame the strong attraction (the strings) you had to each other. As more heat was added, you moved faster still, and moved farther apart, but you were still moving slow enough to hold on to each other, just like molecules in a liquid. However, enough heat was finally added that you could no longer hold on to each other, and you went off in all directions like molecules in a gas.
