Creating Crystals Using Basic Household Ingredients and Supplies

http://www.beloit.edu/~SEPM/Rocks_and_minerals/growing_crystals.html
http://www.micro.magnet.fsu.edu/optics/activities/students/variables.html

This experiment is intended for grade 5 students and can be used in the ``Classroom Chemistry`` unit.

General Learner Outcomes:
· Carry out an investigation using given procedures and expand on this investigation
· Interpret observations and apply to knowledge they have acquired.

Specific Learner Outcomes:
· Create a prediction/hypothesis by providing answers to a given question.
· Record observations and create a conclusion based on experimental results.
· Identify new questions based on what they have learned.

Basic Procedures:

The student will only complete the first part of the excercise where they are growing alum and salt crystals at room temperature and in the refrigerator. After they have allowed the crystals to grow overnight, they should be able to answer the following:
a. How are the salt crystals different from the alum crystals? Talk about the shape, size and color. You may draw a picture if that helps. Create a table that compares and contrasts the crystals.
b. How are the crystals different when crystallization occurs at room temperature and when it occurs in the refrigerator? Create a table that compares and contrasts these characteristics.
c. What was the constant variable in the experiment?
d. Describe in your own words what “crystallization” means and how temperature affects crystallization.
e. Write down 3 new questions that you have about crystallization.
f. What other things would affect the shape, size, or color of a crystal?

Ask the students to re-dissolve the crystals. They must decide for themselves the best way of dissolving the crystals. Ask the students to answer the following questions:
g. Did the crystals redissolve in water and what did you have to do to make them dissolve?
h. What other techniques could you use to get the crystals to dissolve?
i. Is crystallization a reversible or irreversible reaction?

ICT Outcomes:

· Students are able to retrieve information from the Internet by using a specified URL
· Students are able to compile information obtained from the activity using a table in Microsoft Word or Excel.

Why use technology in the lesson?

The use of technology in this lesson allows the student to see the types of information and experiments they can find on the internet. By compiling the information in tabular form on the computer, they are seeing the effects of formalizing data and creating clear observations that can be shared amongst their classmates.

References:

Davidson, M.W., (2003, Aug 1). Science, Optics and You: Activities in Optics. Center for Integrating Research and Learning. Retrieved September 29, 2007 from
http://www.micro.magnet.fsu.edu/optics/activities/students/variables.html

Beebe, M.A., (2003, August). Growing Crystals. Society for Sedimentary Geology. Retrieved September 29, 2007 from
http://www.beloit.edu/~SEPM/Rocks_and_minerals/growing_crystals.html