Table of content
1. Full Form of UV
2. A brief history of UV
3. UV properties are:
4. Use of UV light
1. Full Form of UV
2. A brief history of UV
3. UV properties are:
4. Use of UV light
Full Form of UV
Ultraviolet (UV) is a type of electromagnetic radiation with wavelengths between 10 nm to 400 nm, shorter than visible light and longer than X-rays. Ultraviolet light is contained in sunlight and accounts for about 10% of the sun's total electromagnetic radiation output. It is also produced by arc flashes and special lights such as mercury lamps, tanning lamps, and black lights. Long-wave UV light is not considered ionizing radiation because its photons lack the energy to ionize atoms, but it can cause chemical reactions that cause many substances to glow or fluoresce. As a result, the chemical and biological effects of UV are greater than simple heating effects, and many practical applications of UV radiation derive from its interactions with organic molecules. In addition, you can also check out our free General Awareness E-book- Download now for all competitive exams.Source: safalta
A brief history of UV
- Ultraviolet light was first discovered in 1801 by German physicist Johann Wilhelm Ritter when he observed that invisible light rays, slightly beyond the violet end of the visible spectrum, darken paper soaked in silver chloride faster than violet light. He called them "(de)oxidation rays" to emphasize their chemical reactivity and to distinguish them from the "thermal rays" discovered at the other end of the visible spectrum last year.
- Although the term was soon adopted and remained popular throughout the 19th century, some said that this radiation was quite different from light (notably John William Draper called it the "Tithonic Ray"). The terms "chemical radiation" and "thermal radiation" were eventually dropped in favor of ultraviolet and infrared rays, respectively.
- In 1878, the bactericidal effect of shortwave light was discovered by killing bacteria.