While these young students have a generally good idea of how the molecules of a solid, liquid, or gas behave, there are some further things they could do to make their modeling activity more accurate.

In a solid, they should be locked together, perhaps holding on to each other’s arms. If the solid were a crystal like a diamond or salt, the individual atoms or molecules are attached to each other in an ordered, repeating pattern called a lattice.

In a liquid, they would be moving in relation to one another, but still be quite close.

Finally, as a gas, they were correct to be spread apart. But their motion should be much more complicated — and they should be moving at all different speeds, bumping into each other and the container walls.