Therese Donatello (St Edwards School): Double Displacement
She made the analogy between displacement reactions and two teams of dancers, male and female, exchanging partners. In other words male: ♂ and female ♀ partners in dance ® positive ions: + and negative ions: - in chemical reactions.
She considered the specific example of softening hard water:
Terry continued with a discussion of chemical nomenclature, discussing the meaning of the suffixes "ide" and "ate", as well as the need to balance the number of positive and negative ions in a compound, so that the net charge is zero (e.g., Fe2O3).
Zoris Soderberg (Webster School)
started out with a discussion of Bessie Coleman, first US black female pilot. She went to France to learn flying, and demonstrated that "nothing is too hard for you if you try hard enough". Then Zoris talked about airplanes, and asked the question as to how planes fly. The answer lies in the air, in that air is a form of matter, and can apply a force to overcome gravity and to keep the plane in the air.
How can you prove that there is air in the room? Zoris took a 1 liter plastic bottle, containing nothing except air. She put the cap on the top lip of the bottle, upside down, and held the bottle with both hands. The cap danced, because of heating of air inside the bottle with her hands. The kinetic energy of air molecules was transferred to the cap, causing it to dance as they hit it.
Next she put water in a Styrofoam™ cup, and put a 3" ´ 5" index card over the top of the cup, and inverted it. Air pressure held the water in the cup, against gravity.
Zoris then mentioned Bernoulli's Principle as an explanation for how air holds up an airplane, but she did not go into the details.
Notes taken by Ben Stark.