To demonstrate that a phosphorescent material when irradiated with UV light will emit light of a lower energy for an appreciable interval of time.
- U.V. light source
- Phosphorescent powder
It is quite dramatic to irradiate the phosphorescent powder together with some other fluorescent material. When the source is removed it is clearly seen that the phosphorescent powder emits light for an appreciable length of time (of the order of ten seconds).