Yes, ozone is created by UV light. Specifically, UV light with wavelengths between 100 and 240 nanometers (nm) is responsible for the formation of ozone.
How UV Light Creates Ozone
Ozone (O3) is formed when ultraviolet (UV) radiation interacts with oxygen molecules (O2). This process involves the following steps:
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UV Light Absorption: A high-energy UV photon is absorbed by an oxygen molecule. This photon has a wavelength between 100 and 240 nm.
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Molecular Dissociation: The absorbed UV photon provides enough energy to break the oxygen molecule (O2) into two individual oxygen atoms (O).
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Ozone Formation: Each free oxygen atom then collides with another oxygen molecule. When these two combine, they form an ozone molecule (O3):
O + O2 → O3
Practical Application: UV Lamps
Shortwave, low-pressure UV lamps are commonly used to generate ozone. These lamps emit UV light at specific wavelengths, typically including:
- 254 nm: This wavelength is primarily used for disinfection. While it can contribute to ozone formation, it is less efficient for that purpose than the 185nm wavelength.
- 185 nm: This wavelength is more efficient at creating ozone, making it ideal for ozone generation.
Understanding UV Light Spectrum
The UV portion of the electromagnetic spectrum is categorized into different bands:
| UV Band | Wavelength Range (nm) | Description |
|---|---|---|
| UVA | 315 - 400 | Relatively low energy, causes tanning |
| UVB | 280 - 315 | More energetic, causes sunburn |
| UVC | 100 - 280 | Most energetic, creates ozone |
As indicated by the reference material, the UV range needed to create ozone is between 100 and 240 nm, which lies within the UVC part of the spectrum.
