Index of Refraction of Water
Bibliographic Entry  Result (w/surrounding text) 
Standardized Result 


Serway, Raymond. College Physics. Sixth ed. Pacific Grove: Brooks/ColeThompson Learning, 2003. 

1.333  
Home, R., ed. Water and Aqueous Solutions. Toronto: WileyInterscience, 1972. 

1.3325  
Gary, Dwight, ed. American Institute of Physics Handbook. 3rd ed.: McGraw Hill, 1972.  [see table below]  1.33121.3435  
Index of Refraction. Hyperphysics. 2005. 22 May 2005. 

1.33 
Substance:  Density  Temp., °C  Indices of Refraction  

0397 µm H 
0.434 µm G' 
0.486 µm F 
0.589 µm D 
0.656 µm C 

water, H_{2}O  …  20  1.3435  1.3404  1.3372  1.330  1.3312 
The index refraction is the ratio of the speed of light in a vacuum to the speed of light in a substance. It is represented by the letter n and can be found through the equation n = c/v, where c is the speed of light in a vacuum and v is the speed of light in the material.
The index of refraction of a material can also be determined by the formula n = λ_{0}/λ_{n}, where λ_{0} is the wavelength of the light in the vacuum, and λ_{n} is the wavelength in the material. The refractive index can also be determined by Snell's Law, which states that n_{1}sinθ_{1} = n_{2}sinθ_{2}, where n_{1} and n_{2} are the indices of refraction in the two media; and θ_{1} represents the incident ray and θ_{2} represents the refracted ray. The index of refraction primarily varies with substance and wavelength. Materials of the same composition can have different refractive indices due to the different conditions that they are in. The absorption and reemission of light is different as it travels from atom to atom; thus, it depends on the structure of the atoms composing each material.
The index refraction of liquid water at 20 °C is 1.333.
Amy Ho  2005