Jeremy Dockan, a chemistry teacher at College Station High School, showed off hydrogen’s colorful side for his students. He applied a voltage across a tube full of hydrogen gas to make the gas glow purplish red. When his students donned diffraction glasses and looked at the glowing tube, the purple-red light separated into the four visible components of hydrogen’s emission spectrum: red, cyan, blue, and faint purple lines. Each color line represents excited atoms shifting between two specific energy levels.—Manny MoroneSubmitted by Jeremy Dockan. Dockan will win a Chemistry in Pictures poster prize pack.
First runner-up: A glowing demonstration
Credit: Cecilia Wisniewski
Students in the Union ChemClub of Union, N.J., enjoyed this glowing demonstration of four fluorescent dyes. Club adviser Cecilia Wisniewski mixed a few drops of each dye with tap water and illuminated them with ultraviolet blacklights at 365 nm and 370 nm. The dyes are used commercially in a range of food colorings, biological stains, and pigments. The purple is from methylene blue, green from fluorescein, blue from Acid Blue 9, and red from Rhodamine WT.—Craig BettenhausenSubmitted by Cecilia Wisniewski. Wisniewski will win a classroom set of goggles.
Grand prize winner: Turn your pennies into ‘gold’
Credit: Rosemarie Pittenger
Rosemarie Pittenger, a science teacher at John P. Stevens High School in Edison, N.J., made the most of her pennies with this demonstration of metallurgy and surface science. To make the silver-looking pennies, Pittenger placed coins in a bath of 1 M zinc chloride solution with small lumps of zinc. Zinc ions in the solution were reduced by the copper on the penny’s surface, producing zinc metal that plated the penny with a thin, silverlike coating. To make the golden penny, Pittenger put one of the zinc-coated coins on a hot plate for a minute or so. The heat made the zinc coating and remaining copper underneath diffuse into each other and mix to form the alloy yellow brass.—Manny MoroneSubmitted by Rosemarie Pittenger. Pittenger will win a hot plate, glassware, and an electronic balance.
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