Refractive index



The refractive index is quoted for the gas or vapour state at 273 K/760 mm Hg for the sodium yellow d-line at 589.3 nm.

image showing Refractive index: period 4sp periodic periodicity for 4s and 4p chemical elements


Air has a refractive index of 1.000292 under these conditions.

Water vapour has a refractive index of 1.000256 under these conditions.

Literature sources

  1. G.V. Samsonov (Ed.) in Handbook of the physicochemical properties of the elements, IFI-Plenum, New York, USA, 1968.
  2. A.M. James and M.P. Lord in Macmillan's Chemical and Physical Data, Macmillan, London, UK, 1992.
  3. G.W.C. Kaye and T.H. Laby in Tables of physical and chemical constants, Longman, London, UK, 15th edition, 1993.

WebElements Shop

WebElements now has an online chemistry shop at which you can buy periodic table posters, mugs, T-shirts, games, molecular models, and more.

WebElements poster Periodic table t-shirts Periodic table mouse mats Molymod molecular model kits Chemistry educational resources