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: Photosynthesis and Respiration: Complementary Processes
Categories: Teacher Demonstration
The cells of green plants contain the pigment chlorophyll in organelles called chloroplasts. Chloroplasts capture the Sun’s energy and store it―through photosynthesis―as chemical energy. The... read more
Teacher Demo: Lung in a Bottle
Categories: Teacher Demonstration
This is a simple, yet extremely effective model of human lungs. Students are able visualize how the lungs, thoracic cavity and diaphragm work together to facilitate inhalation and exhalation. This... read more
Student Activity/Teacher Demo: Spinning Dish
Categories: Lab/Student Activity, Teacher Demonstration
In this demo, two polyethylene strips are charged on one end by rubbing with wool. One charged strip is then mounted on an evaporating dish and the other charged strip is used to make the dish spin.... read more