Growing Crystals Experiment By Cole and Anna B.

Question How do you grow the biggest and purest crystals? What are the best temperatures and conditions for growing crystals? How long do they take to form?

Background Information Using chemical reactions you can make crystals. Hot water will dissolve more particles than cold water. A crystal is made of molecules. Crystals are made in a repeating pattern. The pieces that don’t match the repeating pattern are called impurities and are rejected.

Hypothesis (If… then…) If you slowly cool the borax, then you will have bigger and clearer crystals.

Materials Notebook Large bowl Ice cubes Water Thermometer String Scissors Three pencils Identical jars or large drinking glasses Cooking pot with lid Measuring cup Borax Tablespoon Plastic wrap Gloves (optional)

Procedure Write hypothesis in notebook Fill large bowl ¼ full with ice and fill up to ¾ with water Use thermometer to take the temperature of room & ice bath Write temperatures in note book, including the fridge temp. Cut three pieces of string and tie them around each pencil and lay on jars (string should almost touch the bottom)

Procedure Continued Fill cooking pot with enough water to fill each jar ¾ full Bring water to boil Once boiling shut off the stove so water is no longer boiling Add one tablespoon of borax to water and keep adding until no more will dissolve Pour solution into jars until ¾ full Lay pencil across jar so string is in solution and cover with plastic wrap Put one on the counter, one in the fridge, and one in the ice bath so the water in the ice bath reaches ¾ up the jar. Leave jars for 5 hours.

Analyze Results Run the experiment 3 times. Fill in a different chart every time Cooling Condition Trial 1 Temperature Time of Crystal Formation (in hours) Number of Crystals Size of Individual Crystals Other Observations Ice bath Refrigerator Room temperature