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.
Categories: Lab/Student Activity, Teacher Demonstration
This demonstration allows students to experimentally determine the speed of light by heating a piece of chocolate in a microwave oven. This demonstration is best used as an enrichment activity as the... read more
Categories: Lab/Student Activity, Teacher Demonstration
In this demo, a polyethylene rod is charged by rubbing with wool. The charged rod is then used to bend a stream of water flowing from a tap. Different substances have different attractions for... read more
Categories: Lab/Student Activity, Teacher Demonstration
In this activity, student mix a given quantity of salt with a fixed volume of water. Mass and volume measurements are made before and after mixing to determine if these quantities change. Students... read more