Powdered Borax is an ionic compound that dissolves easily in warm water. When given a surface to attach to, the borax will reform into crystals that are quite large.
Borax is a natural mineral with a chemical formula Na2B4O7 • 10H2O. The scientific name for borax is sodium tetraborate decahydrate. Borax is also known as sodium borate, sodium tetraborate or disodium tetraborate. It is one of the most important boron compounds.
In this activity a saturated solution of Borax and water is prepared. As the solution cools the crystals come out of solution and form on the textured pipe cleaner. When the crystals dry, they are interesting both tactually and visually.
Materials
Pipe cleaners
Pencil or stick
Hot water
Large beaker (or wide mouth jar)
Stirring rod or spoon
50 g. powdered Borax pre-measured in paper cup (About half a cup)
Tray
Goggles
Aprons
Gloves if desired
Preparation
Make a shape in one end of the pipe cleaner. This is where the crystals will deposit as they form.
Wrap the other end of the pipe cleaner around the middle of the pencil or pen.
Rest the pencil on the top of the beaker. Check that the pipe cleaner shape is hanging in the middle of the beaker and is not touching the sides or bottom of the beaker.
Remove the pencil and pipe cleaner and place on the left side of your tray if you are left handed. Place it on the right side if you are right handed.
Use a talking or large print read out scale to weigh the borax.
Procedure
Place beaker in the center of your tray.
Fill your beaker with approximately 3 cups of hot water ( approximately 700 mL).
Add the pre-measured borax and stir until the borax is dissolved. You will notice the mixture no longer feels gritty as you stir.
Carefully place the pencil or stick with the pipe cleaner shape attached on top of the beaker.
Check visually and or tactually that the top of the shape is covered with solution.
Allow the beaker and solution to remain untouched for a day.
Remove pencil and the attached shape, placing it in an empty beaker to drip dry for another 24 hours.
Examine the pipe cleaner shape visually and/or tactually.
Dispose of the borax solution by pouring down a sink drain and rinsing for several minutes with hot water.
Variations
Less water, about 2 cups per 50 g of BoraxTM will result in denser crystals. But all of the Borax may not initially dissolve.
The finished crystal makes a great holiday ornament
NGSS Standards
PS1.A Structure of matter: The fact that matter is composed of atoms and molecules can be used to explain the properties of substances, diversity of materials, states of matter, phase changes, and conservation of matter. (Grades 6 to 8)