- Dissolving Challenge:
a. Students pour one cup of warm water into each of two glass cups
b. Students add a teaspoon of powdered or confectioners' sugar in one cup and a teaspoon of granulated sugar in the other.
c. They observe which dissolves faster and answer questions regarding how surface area impacted the results
- Crystal Challenge:
a. Teacher/adult first pours one cup of very hot water in to each of the two cups.
b. Students add 3 cups of each type of sugar into individual cups and stir to dissolve -- the water will appear perfectly clear when the sugar is dissolved. Note - alternate approach is to boil the water to dissolve the sugar -- if this approach is taken, an adult should prepare boiled sugar solutions.
c. Soak the string into the sugar water and tie one end to the pencil so that the other end hangs vertically in the sugar solution. A weight (washer, screw) can be added to ensure the string stays straight. You may also prepare the strings ahead of time, soaking them in the sugar solutions and letting them dry. With this method, there will be starter crystals on the string before being placed in the sugar solutions which can speed up the crystal process as the starter crystals provide a place for new crystals to form.
d. Observe the cups each day for four - seven days
e. Record observations during growth
f. Examine each of the resulting crystals under a microscope and record observations in table provided.
- Evaluation - Students complete evaluation/reflection sheets