Borax Crystal Ornaments

A little late for the holiday season, but better late than never. One of the standards my students have to learn is the repeating pattern of the crystaline lattice. With a little bit of time before break (and after a unit test), my students were able to make some Borax crystal holiday ornaments (and they took their ornaments home). The video shows the making of process, which my students did. After they return from break, we will go into the nitty gritty science part of the crystal formation.

Refrigerators and Chemical Reactions

What does a refrigerator have to do with chemical reactions*? Watch the video to find out.

*A clock reaciton kit was used in the video. You can order one here.

Soda Can Density Discrepancy

Demonstrating the density of diet sodas versus regular sodas is a classic, but something unexpected happened when I placed a can of Dr. Pepper and A & W root beer in a tank of water. They didn't follow the usual pattern of results. Watch the video and please respond if you can provide an explanation for the results.

Hot and Cold Water

What happens to hot and cold water when placed in room temperature water? What if the water is colored? Watch the video for a simple demonstration of the properties of hot and cold water.

Styrofoam, or Polystyrene Cup

The Styrofoam cup. It seems like a simple unitasker, one that holds liquids and is a good insulator. Why is it a good insulator and so light? Styrofoam is the the brand name that Dow Chemical uses for its version of polystyrene. Polystyrene is a polymer, which is a substance that is made up of repeated units, monomers, bonded together. What makes Styrofoam special is the process in which it is made. During the process, gas is blown into the polystyrene causing the material to be mostly empty space. The Styrofoam is very low in density becuase the mass of the polystyrene is contained in a larger area. It is a good insulator because the air spaces that make up the foam deters heat energy flow. The above video demo shows what happens when the polystyrene is dissolved in acetone. The polystyrene structure basically collapses and condenses, leaving a hardened, more dense mass.