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WHAT WILL YOU DO?:
What do snowflakes, rock candy and quartz have in common? All of these
are
crystals!
Crystals are formed when certain substances solidify
(become solid - like liquid water freezing
to become
solid ice). When you examine a crystal, you can see that it has a
repeatable pattern.
In this activity you will make an edible crystal
and examine its beautiful structure with a magnifying glass!
SAFETY NOTES:
ADULT SUPERVISION REQUIRED
This experiment should be conducted by an adult(s), not students.
Very hot liquids and glass jars are used.
Consider making a sample one week in advance.
STEPS TO FOLLOW:
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You may want to grow some crystal samples one week in advance.
Using the wooden spoon, mix 2 cups of water and
5 cups of sugar in a pan. Stir over heat until the
sugar
is dissolved. Continue heating until the solution is at least 250
oF or until it has reached
the "hard ball" stage. (You can use the candy thermometer
to determine this.) This makes 4 cups (8 - 8 ounce portions)
of sugar solution.
Let the solution cool slightly. (If you wait too long the solution
may start to harden.)
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The string for the rock candy should reach from
the top of the jar to the
bottom.
Cut a piece of string this length and long enough to tie
a paper clip on the end.
Tie a paper clip onto one end of the string.
Tape the other end of the string to the center of the lid.
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MATERIALS:
Small (6-12 ounce) Clean Jar With Lid*
Sugar Crystals Grown In Advance
Sugar Solution - 6-8 ounces Per Student - See Step 2
Sugar (5 Cups Of Sugar For Every 8 Students)
Water
String (Approximately 6 Inches Per Student)
Paper Clip (One Per Student)
Wooden Spoon
Ladle
Transparent Or Masking Tape
Measuring Cup
Magnifying Glass
Other Crystal Samples (Such As Quartz Or Ice) Or
Pictures
Candy Thermometer (Optional)
(Note: *Have each student bring a small jar. Bring some extra
jars as a backup.)
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Pour 6-8 ounces of the sugar solution into the jar.
The string cannot
touch any portion of the jar
when it is closed, but must be partially submerged.
Screw the lid on loosely to allow a little evaporation. Place the
jar where it won't be disturbed.
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Students should close the jar tightly when they transport
their jars home.
Once the jar is in a place where it will not be disturbed,
students should
unscrew the lid until it is a bit loose
to allow a little evaporation.
Wait at least
one week for the crystal to grow. (Note: This is rock candy and is edible.)
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Students should visually inspect the crystals grown as well as
examine them using a magnifying glass.
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