The purpose was, to investigate the different types of crystals formed by evaporating solutions of two common household substances, Salt and Alum. To carry out this experiment, mark six petri dishes with numbers one through six. Then pour Alum in the first three dishes. The remaining Alum
should go into a glass, with a string attached to a washer, hanging into the glass. Fill the other threedishes with Salt. Wait seventy- four hours, and then record the different shapes of the crystals. In the four trials, Alum had an average of 3.5. In the trials Salt had an average of 2. The glass with Alum also had an average of 2. I accept my hypothesis.These results happened because salt crystals are cubed. While alum crystals can be hexagonal, triangular or cubed. The biggest trouble was finding the Alum; it took fifteen grocery stores and drugstores to finally find it. If this experiment had to be done again, the alum would have been shopped for much earlier. Instead of actually driving to the stores, they could have been called.
Alum has application to studies of molecular makeup. The specificcrystal form shape can be used as a form of identification characteristic.
The experiment could be expanded to see if instead of Salt, another substance grew more forms of crystals then Alum. Or, one last way would be to find other substances that have a similar chemical or molecular structure, and see if they grew crystals of similar shape.

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