Phosphorescence

Definition

Phosphorescence is the emission of light by a substance that has absorbed light or other electromagnetic radiation and continues to emit light after the excitation source is removed. It differs from fluorescence in that the emitted light persists for a longer duration.

5 Must Know Facts For Your Next Test

1. Phosphorescence occurs when certain materials emit light without heat after being energized by an external light source.
2. In microbiology, phosphorescent materials can be used to label and track biological molecules or structures under specific conditions.
3. The phenomenon is due to the transition of electrons from a higher energy state to a lower one, with delayed re-emission of photons.
4. Phosphorescence is often observed in marine organisms like jellyfish and some types of algae, which may have applications in studying marine microbiology.
5. This property is exploited in various scientific imaging techniques to enhance visibility and contrast of microscopic entities.

Review Questions

• What distinguishes phosphorescence from fluorescence?
• How does phosphorescence help in tracking biological molecules in microbiology?
• Why do some marine organisms exhibit phosphorescence?

Related terms

Fluorescence:

The emission of light by a substance that has absorbed light or other electromagnetic radiation, ceasing almost immediately when the excitation source is removed.

Bioluminescence:

The production and emission of light by living organisms as a result of chemical reactions within their cells.

Photoluminescence: Light emission from any form of matter after the absorption of photons, encompassing both fluorescence and phosphorescence.