As an engagement piece to get students attention about fluorescence and phosphorescence, gather several objects that glow in the dark (phosphorescent) and others that are fluorescent. These objects are especially available around Halloween.
Objects to use:
Laundry detergent
Glow in the dark paint or chalk
Tonic water with quinine
Toys which are fluorescent or phosphorescent
Rocks that show fluorescence
Procedure:
Set up a blacklight and turn down the lights.
Show the various objects and explain to students that fluorescent objects will not glow when the energy source (in our case, the blacklight) is removed, but phosphorescent objects will.
Ask students if they think the various objects are fluorescent or phosphorescent.
Turn off the blacklight. Now, ask students to identify which objects are fluorescent and which are phosphorescent.
Additionally, when salt is added to the tonic water, the tonic water loses its fluorescence. So this can be demonstrated as well. It is the quinine that is fluorescent in the tonic water.
At this point, make sure to emphasize that the phenomena of fluorescence, phosphorescence, and chemiluminescence all involve electrons.