About
this Daily Classroom Special:
Science to Go provides easy yet meaningful
science activities for grades k-8. Science to Go was written
by Barbara Smith, Magnet Coordinator at Harvard Elementary, Houston
(TX) and former Teachers Network web mentor.
Here's an activity my students love
to watch!!
Magic Crystal Gardens
Materials: (per sample or group)
- 3-5 charcoal briquettes (plain, without lighter fluid added)
- hammer or rock
- small container for mixing ingredients
- water
- table salt
- laundry bluing
- measuring spoon
- plastic plate
- masking tape and permanent marker (optional)
- food coloring
Procedure
- Use hammer or rock to break briquettes into large chunks. Place
chunks on plastic plates.
- Measure 2 tablespoons each of water, salt, and laundry bluing
into container, and mix well.
- Pour mixture over briquettes.
- Mark plate with tape and marker (if you are making several
samples. See below.)
- Set aside in a warm dry place.
- Day Two: Add 2 tablespoons salt to the puddle around the charcoal.
- Day Three: Repeat step b , pouring the mixture onto the plate,
not directly on the charcoal.
- Add several drops of food coloring directly to the charcoal.
- Set aside and observe for several days. If you would like to
speed it up, add one tablespoon of household ammonia in steps
b and g.
*If your crystals begin to outgrow your container, wipe a thin
film of petroleum jelly around the rim of the plate.
Give students old towels, shirts, or aprons to protect their clothing
from accidental bluing splashes.
Want to make it into an experiment?
If your students are ready for experimental design, make several
samples, changing one variable. For example, you can change amounts
of water, temperature of resting place, number of briquettes, temperature
of water, shape of container, etc. Currently, my fourth-graders
are testing whether water temperature will affect the size of the
crystals grown.
What's happening here?
Laundry bluing is a suspension of Fe2Fe3(CN)6 particles, and is
used as a laundry additive to whiten clothing. As the water in your
solution evaporates, the dissolved salt begins re-crystallizing,
building around the bits of bluing which act as crystal nuclei.
The charcoal acts as a sponge, increasing the surface area and the
evaporation rate.
Website Picks for Science
Henry Ford Museum:
Activities for children and teachers. Open Educational Program.
Aliceville:
Run by Argo Enterprises, this site contains projects for young children,
children's books recommendations, and easy snack recipes. Check out
Arts & Crafts - its more than it sounds to be. |
