In this demonstration, a chemical reaction is used to make a hidden message visible. The demonstration illustrates an entertaining application of chemical reactions in toys and everyday objects. It is also an interesting way to start the discussion of acids and bases, the pH scale, or acid-base indicators. Invisible ink has been used in espionage to send messages that cannot easily be read by enemies.
Related Resources:
Teacher Demo: Potato Candle
Categories: Teacher Demonstration
In this demonstration, a peeled potato is cut into the form of a candle and an almond slice is used as the candle’s “wick.” The teacher lights the almond slice on fire and it burns. The... read more
Teacher Demo: Acid-Base Rainbow
Categories: Teacher Demonstration
This quick demonstration is a highly visual illustration of the use of acid-base indicators to determine pH. Milk of magnesia is mostly a suspension of magnesium hydroxide in water. Magnesium... read more
Teacher Demonstration: The Force of Air Resistance and the Speed of an Object
Categories: Teacher Demonstration
Most of us know from experience that the force of friction caused by air resistance increases as the relative speeds increases. The purpose of this activity is to develop a proportionality statement,... read more
