Students will work in groups of two to measure pH of freshwater system when crayfish are present in water sample. A control will be set-up and the biology of the crayfish will studied. The pH should increase as the crayfish releases ammonia as a waste product. (Ammonia is a base)
Often students cannot understand from chemical formulas how atoms exist in compounds, and how they are rearranged during reaction. Furthermore, the concept of balancing reactions eludes them when they cannot actually see the individual atoms. To illustrate a reaction for them, They are split into groups and given "bingo" type chips of different colors. They then put them into groups as reactants, representing the compounds that enter the reaction. They will then break the bonds of the reactants and attempt to rebond them as products. In most reactions, they will see that without balancing they do not have enough "chips" to complete the reaction. However, if they add more of one or more of the reactants, they can then complete the reaction because they now have enough "chips". They will then transfer findings to a sheet, written as a balanced formula equation.
Using the COW, students will use either the program FRAMES or the flip camera and movie maker (their choice) to animate a chemical reaction in order to illustrate that all atoms involved are present at the beginning and end of the reaction, and that matter is neither created or destroyed.