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Ultraviolet radiation, also known as simply UV, is electromagnetic radiation of wavelengths of 10–400 nanometers, shorter than that of visible light, but longer than X-rays. UV radiation is present in sunlight , and constitutes about 10% of the total electromagnetic radiation output from the Sun.
Next in frequency comes ultraviolet (UV). In frequency (and thus energy), UV rays sit between the violet end of the visible spectrum and the X-ray range. The UV wavelength spectrum ranges from 399 nm to 10 nm and is divided into 3 sections: UVA, UVB, and UVC.
Electromagnetic radiation in this range of wavelengths is called visible light (or simply light). The optical spectrum is sometimes considered to be the same as the visible spectrum, but some authors define the term more broadly, to include the ultraviolet and infrared parts of the electromagnetic spectrum as well, known collectively as optical ...
where λ is the wavelength of the absorbed/emitted light and R H is the Rydberg constant for hydrogen. The Rydberg constant is seen to be equal to 4 / B in Balmer's formula, and this value, for an infinitely heavy nucleus, is 4 / 3.645 0682 × 10 −7 m = 10 973 731.57 m −1. [3]
The light source consists of a Xenon flash lamp for the ultraviolet (UV) as well as for the visible (VIS) and near-infrared wavelength regions covering a spectral range from 190 up to 1100 nm. The lamp flashes are focused on a glass fiber which drives the beam of light onto a cuvette containing the sample solution.
The UV power spectrum (expressed as watts per square meter per nanometer of wavelength) is therefore multiplied by a weighting curve known as the CIE-standard McKinlay–Diffey erythemal action spectrum. [9] [10] There are some older formulas for the spectrum, resulting in differences of up to 2%. [11] The result is integrated over the whole ...
Visible light is an electromagnetic wave, consisting of oscillating electric and magnetic fields traveling through space. The frequency of the wave determines its color: 400 THz (4 × 10 14 Hz) is red light, 800 THz (8 × 10 14 Hz) is violet light, and between these (in the range 400–800 THz) are all the other colors of the visible spectrum.
The version of the Rydberg formula that generated the Lyman series was: [2] = (= +) where n is a natural number greater than or equal to 2 (i.e., n = 2, 3, 4, .... Therefore, the lines seen in the image above are the wavelengths corresponding to n = 2 on the right, to n → ∞ on the left.