Page 186 - Demo

Flinn Lab Activities and Demonstrations
Polymers—Demonstration Kits, continued
Ghost Crystals
A vial appears to contain only water and a small
string noose hanging down into it. When the string is
lifted out, a large shiny crystal is found to be tied up
in the noose. When the string is lowered back into the water, the crystal again becomes invisible! Instructions included.
See free video at flinnsci.com.
April Fool’s Day—
Multi–Demonstration Kit
By: The Flinn Staff
Celebrate April Fool’s Day with the unexpected! Four discrepant event demonstrations engage students’ curiosity using the element of surprise.
• An open jar of water is covered by a laminated card and turned upside-
down. Air pressure holds the card in place. Remove the card and the water stays in the jar!
• Surely the balloon will pop when a skewer is poked through it. Not so!
• The liquid in the U-shaped tube is not level! Have fun as students make suggestions to explain this phenomenon.
• Two identical balloons, inflated to different volumes, are connected. What will happen when the pathway is opened and air is allowed to flow between the balloons? The outcome is surprising . . . but should it be?
Contains enough materials to perform each demonstration seven times. Concepts: Surface tension, air pressure, cohesion, polymers, cross- linking, density, pressure of fluids, observation, minimum energy state. Time Required: One class period
Materials Provided: Blue food coloring, sodium chloride, balloons, canning jar with ring lid, laminated card, clamp, corks, sandpaper, nylon screen, wooden skewers, rubber stoppers, latex tubing, clear plastic tubing, soft glass tubing.
See free video at flinnsci.com.
Chemical Wizardry—
Multi-Demonstration Kit
By: The Flinn Staff
Mesmerize your students with three spell-binding demonstrations! First, set the mood as you generate the eerie glow of a green flame by sprinkling boric acid over a gel created with calcium acetate and ethyl alcohol. Next, add to the atmosphere of enchantment by transforming a solution into slimy, ghoulish, glowing polymer worms. Complete the spooky scene with a secret message written in blood-red ink made from an iron compound. As students observe the results of your wizardry, they learn important chemical concepts at the same time. Includes detailed Demonstration Notes and a reproducible student worksheet. Concepts: Gels, atomic emission, polymers, cross-linking, fluores- cence, complex ions, chemical reactions.
Time Required: 30 minutes
Chemicals Provided: Boric acid, calcium acetate, ethyl alcohol, calcium chloride solution, copper(II) chloride solution, fluorescein,
sodium alginate solution, iron(III) chloride solution, potassium thio- cyanate solution.
1-800-452-1261
flinnsci.com
184
Catalog No.
Description
Price/Each
G0050
Ghost Crystals, 100 g
$ 8.00
G0052
Ghost Crystals, 500 g
22.00
Ghost Crystals G0050, etc.
April Fool’s Day— Multi-Demonstration Kit AP7327
Catalog No.
Description
Price/Each
AP7327
April Fool’s Day—Multi-Demonstration Kit
$48.90
Chemical Wizardry— Multi-Demonstration Kit AP7503
Catalog No.
Description
Price/Each
AP7503
Chemical Wizardry— Multi-Demonstration Kit
$54.00