Project Seeing the Light in Chemistry

Stephen spends a lot of time in the basement. That's where he built his home chemistry lab. "I like chemistry and biology because they are becoming so interdisciplinary," he says. "I can find a way to mix them with every other science."

devience project
Stephen J. DeVience with the spectrophotometer he designed and built for identifying chemicals
Mixing chemicals is something he does a lot of. The job would be easier with a spectrophotometer, an instrument that can reveal both the identity and relative concentrations of a mixture's chemical constituents. But these gadgets are fairly expensive, so he was making do without — until he read about the photoelectric effect in Linus Pauling's General Chemistry, the first chemistry textbook based on quantum mechanics. The photoelectric effect relates to light energy's dual nature — it can be either waves or particles called photons — and how photons interact with electrons to generate electricity, with the voltage determined by the light's wavelength.

That got the wheels turning. Stephen reasoned he could essentially reverse that process by using negative voltages to wipe out one or more corresponding colors. Then an ordinary full-color phototube detector could select any specific color, just like a regular spectrophotometer — but without the delicate mechanical filters that select colors in commercial units. In fact, Stephen's photoelectric effect spectrophotometer has no mechanical parts. So he figures it would be just the ticket for field inspectors to lug around for on-the-spot tests of potable water and industrial wastewater.

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Notre Dame High School for Boys
Niles, Ill.

Hobbies: Fishing, hiking, astronomy, community service

Ambition: Bio-medical engineering