Question

SI unit of wave number​

Answer 1

• Wave number is expressed in reciprocal meters (m-1).
• The wave number for an EM field is equal to 2 pi divided by the wavelength in meters.
• (In some references, it is defined as the reciprocal of the wavelength in meters; in still others, it is defined as the reciprocal of the wavelength in centimeters.)

Answer 2

Wave number, a unit of frequency in atomic, molecular, and nuclear spectroscopy equal to the true frequency divided by the speed of light and thus equal to the number of waves in a unit distance. The frequency, symbolized by the Greek letter nu (ν), of any wave equals the speed of light, c, divided by the wavelength λ: thus ν = c/λ. A typical spectral line in the visible region of the spectrum has a wavelength of 5.8 × 10-5 cm; this wavelength corresponds to a frequency (ν) of 5.17 × 1014 Hz (hertz equals one cycle per second) obtained from the equation. Because this frequency and others like it are so extremely large, it is convenient to divide the number by the speed of light and hence reduce its size. Frequency divided by the speed of light is ν/