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)

• 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

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

TemperatureTime of Crystal Formation(in hours)

Number of Crystals

Size of Individual Crystals

Other Observations

Ice bath

Refrigerator

Room temperature