HTML version can be found at: http://amasci.com/amateur/gold.html WARNING: on 4/98 somebody bought some Astrobrights Goldenrod paper which DID NOT WORK, it did not change colors. Therefor, run out and buy reams of "goldenrod" quickly, before the "good" kind is entirely replaced with the "useless" kind. Also, take some baking soda to the stationery store, so you can test the paper (the "good" kind will turn red when moist baking soda is rubbed on it.) -------------------------------------------------------------------- THE "GOLDENROD PAPER" SECRET (c)1996 William J. Beaty Office supply stores and Kinko's copy centers sell a type of paper called Astrobrights(tm) Galaxy Gold. It's "goldenrod" in color, sort of a yellow/orange. Big deal. However, IF ALKALINE SUBSTANCES HIT IT, IT TURNS MAGENTA! Spray it with Windex, and it instantly turns bright red! Cool!! Astrobrights Galaxy Gold paper is the worlds largest acid/base indicator strip. Dip it in a base solution (like ammonia cleaner, baking soda in water, etc.) and it turns bright red. Dip it in acid (vinegar, lemon juice, etc.) and it turns yellow again. (Note: there are other brands of goldenrod which do not work. If in doubt, wet a sample of the paper with ammonia glass cleaner. Kinko's usually has bottles of Windex around) The fact that an 8.5 x 11 sheet of goldenrod is enormously larger than your typical acid/base test strip makes numerous classroom demonstrations possible that never could be done before. =========================================================================== TRY THESE: Cut it into strips, dip it in acid or base. It turns colors. duh. Dip it in base so it turns red, then dry it out. This gives you acid-indicating paper which starts red and turns yellow. Put dilute vinegar in one jar, baking-soda solution in another. (Baking soda dissolves better in warm water.) Use paintbrushes to paint on the goldenrod. Baking soda solution turns the yellow paper red. The vinegar solution turns previously-reddened paper yellow. Paint an invisible picture with vinegar on yellow goldenrod, let it dry, then spray it with baking soda solution. It turns red everywhere except the places having vinegar. Draw "invisible" patterns or messages on the paper with rubber cement, diluted Elmer's glue, transparent tape, etc., then spray it with alkaline solution. The paper turns red except where your drawing has sealed it. Yellow artworks on red background appears. Wet a strip of previously-reddened goldenrod, then lower the strip into a half-full glass of carbonated beverage. Don't let the strip touch the liquid. The strip turns orange as the transparent pool of carbon dioxide forms carbonic acid in the wet strip. This lets you "see" the invisible pool of CO2 gas which fills the cup. Dust your hands with baking soda. Claim that you have "Alien DNA Test Paper," and if it turns red, it indicates that you are not human. Have your audience put their thumbprints on some wet Goldenrod paper. Anyone with baking soda on their fingers (you!) will leave a thumbprint which slowly turns red. ELECTROLYSIS: wet some goldenrod paper with salt water and place it on a sheet of aluminum foil. Use clipleads to connect the positive terminal of a 6v or 9v battery to the foil. Connect a wire to the negative battery terminal. Now drag the negatvie wire across the wet goldenrod, and it turns red. Write with electrochemistry! If you reverse the polarity of the battery, you can erase your red drawings. If you replace the goldenrod with previously-reddened paper, the reversed battery connections let you draw in yellow on a red background MY OLD ACID RAIN DEMO: Wet the inside of a glass jar. Light a match, blow it out, then collect the smoke inside the upside-down jar. After awhile the drops of water collect nasty combustion products from the smoke and become acidic. Touch the drops to previously reddened goldenrod paper, and it turns yellow, indicating acid. Instant acid rain! And might you think twice about smoking cigarettes and putting acid in your lungs? I thought up this one while working at the Museum of Science in Boston. ------------------------------------------------------------------ NOTE: Young kids shouldn't perform the following demonstrations. Ammonia is somewhat toxic, is nasty if inhaled, and is dangerous if splashed in eyes. Adult supervision only. Wear safety goggles. ------------------------------------------------------------------ AMMONIA DEMOS: Wet some goldenrod paper, then drip some ammonia-based cleaner upon it. Notice that the red drops have red haloes around them? Just the ammonia fumes turn the paper red. Wet some goldenrod paper. Put some ice cubes in a jar, then pour in a little ammonia and wait for some cold ammonia gas to build up. Carefully pour the transparent ammonia gas over the wet goldenrod paper, and it flares red. Dip a wet strip of un-reddened goldenrod into the seemingly-empty jar, and you'll discover the depth of the pool of cold ammonia gas. Make wet marks on dry goldenrod, and when cold ammonia gas is poured over it, the wet marks turn red. Use a smoke-ring box to shoot invisible ammonia "smoke rings" at wet goldenrod paper. Little red puffs appear where they hit. Freak out Kinko's copy employees by buying one sheet of goldenrod, asking for the bottle of glass cleaner, then yelling "look!" while spraying the paper with the ammonia-based cleaner. But be warned, I've been doing this for awhile, so the secret is spreading from Kinkos to Kinkos like a mind-virus. They may already know about it. ----------------------------------------------------------------------- The Goldenrod Paper Secret was passed on to me by Dr. Roy Gould of CFA, who got it from his brother, an R&D chemist, who heard about it as the "secret" traveled from chem lab to chem lab across the country.