To highlight what is actually happening inside the atom in fluorescence, phosphorescence, and even chemiluminescence, either get a student volunteer to help, have the whole class do the activity, or do it yourself.
Here, I have outlined the activity as if a whole class is doing it.
Tell the students that they will pretend to be electrons and to stand up.
Tell students that when the black light is turned on, they are to get on top of their chairs, but then immediately step back down.
Tell students that they must continue this process until the energy source (blacklight) is turned off.
Tell students to do the activity.
When done, tell students that this represents fluorescence.
Have students repeat the activity, but this time, tell them to stay on their chairs for a longer period of time, even if the black light has already turned off.
Tell students that this second simulation represents phosphorescence.
Discuss with students the similarities and differences between fluorescence and phosphorescence based on their experience. Then, add in how chemiluminescence and bioluminescence are similar, but slightly different.
Optional: You can give students colored plates to throw (though not recommended if it is an entire class) to represent that light is being emitted.
In fluorescence, phosphorescence, and chemiluminescence, the electron absorbs energy from an energy source, and goes to a higher energy level known as the excited state. The electron returns to the ground state, and gives off light. In fluorescence, the excited state is very unstable, so the electrons immediately return to the ground state—the reason why the object stops glowing when the energy source is removed. In phosphorescence, the excited state is more stable, so the object can still glow, even when the energy source is removed. In fluorescence and phosphorescence, the energy source is often light (in the simulation, it was ultraviolet light from the black light). In chemiluminescence, the energy source is from the chemical reaction. This is a good time to then show the demonstration of the oxidation of luminol. Then, mention that in organisms, when light is emitted from a chemical reaction (chemiluminescence), it is called bioluminescence.