Box of Atoms
How To Use
This demo is very useful for explaining the difference between Solids, Liquids and Gasses.
- First explain to the children that the ping pong balls represent atoms.
- For Solids, just let the ping pong balls lay in the bottom, like the picture above. The point is that each atom does move relative to its neighboring atoms.
- For a Liquid, tip the box up one its side and let the balls gently roll over each other. The point here is that in a liquid two atoms do not stay next to each other, however the liquid is still almost a dense as the solid. It only takes up a tiny amount of space in the bottom of the box.
- Finally to demonstrate a Gas you can shake the box all over. You want the balls to be violently bouncing off of each other and the walls and filling up the entire volume of the box. The point here is that gasses fill up a lot of space because the atoms are far apart, but when two atoms come together, they bounce off each other and go in random directions.
How To Build
I went to Multicraft Plastics here in Portland and had them cut me 6 pieces of Plexi-glass (Acrylic). I made the long holes for handles by drilling two 1" diameter holes then I connected the 2 holes by cutting from the edge of one hole to the other with a hack saw. Be careful not to crack your plexi-glass. At first I tried to glue the pieces together with special glue made for plexi-glass, but that did not hold together well enough, so most of my box is held together with clear packing tape. That works well. Don't attach the top until you fill it with ping pong balls. The goal is to have a box that is light weight enough that you can shake it all over, yet strong enough that it will not break apart. The whole thing cost me about $85.00.