Jun 22 2009
Fun with Light Sticks
Some Chemical reactions produce heat and light, a candle burning is one such example as you have light from the flame as well as the heat produced by the flame. It is not as common for a chemical reaction to produce the light without producing heat. There are some examples of chemical reactions that produce light without heat and one of them is a living organism, the Firefly.
Modern technology has produced something that many of us are familiar with and that is the light stick. A plastic tube that contains chemicals, that when activated, the light stick glows or produces light. Here are few fun things you can do to experiment and learn about the light stick. So go find a light stick at a hobby shop, outdoor sports shop, or even at most dollar stores.
Follow the directions on the light stick wrapper to activate it – most of them, you are bending them to break an inner glass vial, then you shake them to mix the chemicals and they begin to glow. First, go into a dark room and observe your light stick – what color is the glow? Does the glow come from the entire stick or just the chemical within the stick.
Now, grab a glass of ice water and immerse the light stick into the water. Does the chilling effect of the water affect the glow? What happened to the glow? Now, get a glass of warm water (not boiling) and immerse the light stick in the warm water – what did you observe about the glow?
Take a break for a day – throw the light stick in your freezer and comeback to it in 24 hours. Is it still glowing? Remove the light stick from the freezer, what happens to the glow of the light stick as it returns to room temperature?
In this fun little exercise, you played with the light stick in various settings, what changes did you observe in the glow? What would you suggest to prolong the glow of the light stick? In the light stick, the faster the reaction, the brighter the glow, thus, the chemical reactance will be used up faster and the light stick will not last as long.
