Eye on Science

In the scientific world, there are three main states of matter: solid, liquids, and gases (most younger students don’t venture in the fourth, plasma, or the fifth [identified in 1995], Bose-Einstein condensates). All matter is made up of atoms and molecules. These states of matter have properties: Compare your artistic photos to this image. How are you able to identify which image represents which state?

Oobleck

Oobleck is an example of a non-Newtonian fluid. It is in fact a liquid. Non-Newtonian fluids’ viscosity (i.e., thickness) varies depending on applied stress. Stress from force will cause non-Newtonian fluids to act more like solids. For further fun, read how Oobleck became a tad problematic in Bartholomew and the Oobleck by Dr. Seuss.

Ivory® Clean

Within about 90 seconds, the Ivory soap will begin to foam and grow to about six times its original size. Physical changes occur when matter goes through a change in size or shape (usually due to a little energy), but the remaining matter is still just (often altered form of) the original matter. For instance, a loaf of bread can be cut into slices, but it is still just bread! You can exert energy and step on an aluminum can, and now you have a crushed aluminum can – different shape and size, still the same matter. Although the Ivory soap is in a different shape and form now, it is still just soap (wet it and it lathers). As the soap warms up from the energy from the microwave, the air and water whipped inside the soap heat up; the water evaporates and the air expands causing the foaming effect. It is similar to popping popcorn in the microwave. This mini-experiment also demonstrates Charles’ Law, “the law of volumes.”

* IVORY® trademark is owned by The Procter & Gamble Company. P&G is not a sponsor of or affiliated with this program.

Balloon Blow-Up

What you have just witnessed is a chemical change. The vinegar (acetic acid) reacts with the baking soda (sodium bicarbonate) and produces a gas, carbon dioxide, which you have trapped/captured in the balloon: NaHCO₃ (s) + HC₂H₃O₂ (aq) ------> CO₂ (g) + H₂O (1) + NaC₂H₃O₂ (aq). Obviously, there was no such reaction with water and baking soda (it is just a mixture). Chemical changes of matter often are subtle. They occur on the molecular level. The changes cannot be reversed and will produce a new substance, evidenced by a color change, an odor, a sound, light/heat produced, or formation of a precipitate or a gas (bubbles!). For instance when you bake a cake, you can’t take out the original egg, the cups of flour, or the water. Your newly produced cake has a changed shape, changed color, and a tempting odor. This mini-experiment can be repeated over and over for fun!

Take some time to investigate the elements found on the periodic table. Here are some songs to help you memorize some:

• They Might Be Giants: "Meet the Elements"
• Primary School: "Periodic Table Song"
• Tom Lehrer: "Chemistry Element Song"