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List of refractive indices. Refraction at interface. Many materials have a well-characterized refractive index, but these indices often depend strongly upon the frequency of light, causing optical dispersion. Standard refractive index measurements are taken at the "yellow doublet" sodium D line, with a wavelength (λ) of 589 nanometers.
[20] [21] Thorium has a characteristic terrestrial isotopic composition, with atomic weight 232.0377 ± 0.0004. [2] It is one of only four radioactive elements (along with bismuth, protactinium and uranium) that occur in large enough quantities on Earth for a standard atomic weight to be determined. [2]
R58 583 + 28% of the value above R550 000. In the 2017/18 tax year 24.2% (993 069) of 3.7 million companies in South Africa had taxable income. Of them, 57.7% of the tax was paid by 370 large companies (0.2% of all companies) with a taxable income in excess of R200 million.
The ammonia molecule has a trigonal pyramidal shape, as predicted by the valence shell electron pair repulsion theory (VSEPR theory) with an experimentally determined bond angle of 106.7°. [36] The central nitrogen atom has five outer electrons with an additional electron from each hydrogen atom.
This is a list of radioactive nuclides (sometimes also called isotopes), ordered by half-life from shortest to longest, in seconds, minutes, hours, days and years. Current methods make it difficult to measure half-lives between approximately 10 −19 and 10 −10 seconds.
Molar concentration (also called molarity, amount concentration or substance concentration) is a measure of the concentration of a chemical species, in particular, of a solute in a solution, in terms of amount of substance per unit volume of solution. In chemistry, the most commonly used unit for molarity is the number of moles per liter ...
This is the list of countries by gross fixed capital formation (GFCP), formerly known as gross fixed investment. The list includes sovereign states and self-governing dependent territories based upon the ISO standard ISO 3166-1. According to World Bank, [1] gross fixed capital formation (formerly gross domestic fixed investment) includes land ...
Since the length of the carbon-carbon bonds is fairly fixed, there are constraints on the diameter of the cylinder and the arrangement of the atoms on it. [18] In the study of nanotubes, one defines a zigzag path on a graphene-like lattice as a path that turns 60 degrees, alternating left and right, after stepping through each bond. It is also ...