Prepare the Goo

• Explain to the students or your children that most materials act like a solid or a liquid, but polymers are molecules that are connected in a certain way that makes them sometimes act like a liquid, and other times act like a solid. Gather together a large jug of white glue, two plastic (not metal, which will interfere with the bonding of the molecules) bowls, a small bottle of Borax (available at most grocery stores in the laundry section), food coloring and a wooden spoon.
  
  

Make the Slime

• Mix half a cup of water with half a cup of glue in one of the bowls, and set aside. In the other bowl, combine a half cup of water with a half teaspoon of Borax. Slowly add the Borax mixture to the glue mixture, stirring rapidly with the wooden spoon. Add a few drops of food coloring to make the slime more interesting. The more Borax solution you add to the glue, the firmer the consistency of the slime. When the gooey slime is complete, give a bit to each child or student. Explain that the more you play with slime, the more the molecules become entangled, making the slime firmer and more like a solid. When you leave the slime alone, the bonds loosen, and the slime oozes and acts more like a liquid.
  
  

Ready the Brew

• Visit a local grocery store and purchase some dry ice (frozen carbon dioxide). Most stores will sell it to the public at a low price. Be sure to handle it with care. Use tongs or heavy gloves, and do not ever let the children touch it, as it will burn the skin. Remind the students that most solids become a liquid, then a gas, but carbon dioxide goes through both stages at the same time. The gas mixes with tiny droplets of water, forming a water vapor or heavy steam which can actually be contained by soap. Advise the students to watch for the mixture of gas and water to float downward, as it is heavier than air.
  
  

Smoke and Bubbles

• Tell the students to watch this science in action. Fill a spooky-looking Halloween cauldron with warm water and a squirt or two of liquid dish soap. For added interest, place a drop or two of food coloring in the water. Then, use tongs to add one piece of dry ice. The soap in the water will surround the gas and water vapor, trapping it in bubbles. The bubbles will then climb up and over the edge of the container, and pop. When each bubble pops, a whiff of "smoke" will escape.