Photoelectric Effect (Cesium)
Cs + hν → Cs+ + e−
Overview
Photons with energy exceeding the work function of cesium (2.1 eV, wavelength < 590 nm) eject electrons from the metal surface. Cesium has the lowest work function of any stable element, making it the most photosensitive metal. Einstein's explanation of this effect in 1905 established the quantum nature of light and won him the Nobel Prize.
Participants
| Role | Substance | Coefficient | State |
|---|---|---|---|
| Reactant | Cesium Cs | 1 | (s) |
Everyday Example
Automatic doors use photoelectric sensors that detect when a person blocks a light beam, triggering the door to open.
Industrial Importance
The photoelectric effect is fundamental to photomultiplier tubes, solar cells, photodetectors, and electron spectroscopy (XPS).
Properties
- Type
- Photochemical
- Reversible
- No
- Energy
- Endothermic
Related Reactions
Chlorophyll Fluorescence
Cis-Trans Isomerization of Retinal
Dye-Sensitized Solar Cell (Grätzel Cell)
Firefly Bioluminescence (Luciferin Oxidation)
Luminol Chemiluminescence
Ozone Decomposition by UV
Ozone Formation by UV Light
Photocatalytic NOx Removal
Photocatalytic Water Splitting (TiO₂)
Photochemical Cycloaddition ([2+2])
Frequently Asked Questions
What is the equation for Photoelectric Effect (Cesium)?
The balanced equation is: Cs + hν → Cs⁺ + e⁻.
What type of reaction is Photoelectric Effect (Cesium)?
Photoelectric Effect (Cesium) is a photochemical reaction.
Is Photoelectric Effect (Cesium) exothermic or endothermic?
Photoelectric Effect (Cesium) is endothermic (absorbs energy).