Spangler Salutes Tom Bindel

Pomona High School-home of Captain Carbon

Pomona High School in Arvada, Colorado is the home of the famous “Captain Carbon,” otherwise known as Dr. Tom Bindel, who has a passion for getting students excited about chemistry. Dr. Bindel is a 2006 Recipient of the Amgen Award for Science Teaching Excellence.


One of Dr. Bindel’s favorite chemical demonstrations is the Visible Catalyst where the Cobalt(II) ion catalyzes the reaction between hydrogen peroxide and potassium sodium tartrate. The demonstration illustrates the properties of a catalyst: (1) a catalyst remains unchanged at the end of the reaction; (2) during the reaction the catalyst undergoes a change (the green intermediate observed during the reaction); (3) the catalyst causes the rate of reaction to substantially increase.

In a spectacular demonstration, students learn that dust explosions are rather common in grain elevators, coal mines, and sawmills. A spark, even due to friction or flame, can set off burnable dust in the air to produce a large explosion. Dr. Bindel’s demonstration illustrates the explosive nature of a powder through the construction of a mini grain elevator explosion. A small paint can is used to represent a grain elevator and lycopodium powder is used as the dust.

Lemon Flash

Say “cheese!”… In the Lemon Flash demo, four lemons pierced with metals are capable of producing enough electrical energy to flash a flashcube.


  • 4 lemons (4 potatoes will also work)
  • 4 galvanized nails (16d)
  • 4 pennies
  • Wires
  • Voltmeter
  • 10,000 mF capacitor
  • 1 flashcube – probably not available anymore; might try ebay (A GE flashcube was used in the demo; do not use MagiCube)


  1. Carefully, pierce each lemon with a galvanized nail (zinc coated iron nail) and a penny, making sure to push the metal in so that about half of it protrudes. Connect one of the lemons to a voltmeter and read the voltage. Disconnect the lemon from the meter.
  2. Place the lemons side by side with a spacing of several inches.
  3. With the aid of wires, connect the galvanized nail of one lemon to the penny of the adjacent lemon, repeating until all of the metals are connected, except for a nail at one of the ends of the lemon chain and a penny at the other end. This constitutes a series electrical connection of the lemons. Connect the ends of this array to a voltmeter and read the voltage. It should be about 4x the voltage recorded for a single lemon. Disconnect the lemons from the meter.
  4. With additional wires, connect the lone galvanized nail and the lone penny to the ends of the capacitor. The purpose of the capacitor is to store enough electricity so that when it is discharged it produces a large enough current to flash a flashcube.
  5. With the aid of a nail point, free two wire loops on the bottom of the flashcube so that each loop opens up to give an exposed end.
  6. With more wire, connect one end of the capacitor to one of the exposed wire ends of the cube. Take a second wire and connect it to the other end of the capacitor. As the free end touches the second wire of the cube, the cube will flash!

Additional Info

Information courtesy of Dr. Tom Bindel, Pomona High School, Arvada, Colorado.

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