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  2. Deuterium - Wikipedia

    en.wikipedia.org/wiki/Deuterium

    Thus, deuterium accounts for about 0.0156% by number (0.0312% by mass) of all hydrogen in the ocean: 4.85 × 10 13 tonnes of deuterium – mainly as HOD (or 1 HO 2 H or 1 H 2 HO) and only rarely as D 2 O (or 2 H 2 O) (Deuterium Oxide, also known as Heavy Water)– in 1.4 × 10 18 tonnes of water.

  3. Rydberg constant - Wikipedia

    en.wikipedia.org/wiki/Rydberg_constant

    The hydrogen spectral series can be expressed simply in terms of the Rydberg constant for hydrogen and the Rydberg formula. In atomic physics , Rydberg unit of energy , symbol Ry, corresponds to the energy of the photon whose wavenumber is the Rydberg constant, i.e. the ionization energy of the hydrogen atom in a simplified Bohr model.

  4. List of physical constants - Wikipedia

    en.wikipedia.org/wiki/List_of_physical_constants

    Rydberg constant: 10 973 731.568 157 ... and is strongly dependent on how those units are defined. For example, the atomic mass constant is exactly known ...

  5. Rydberg formula - Wikipedia

    en.wikipedia.org/wiki/Rydberg_formula

    In 1890, Rydberg proposed on a formula describing the relation between the wavelengths in spectral lines of alkali metals. [2]: v1:376 He noticed that lines came in series and he found that he could simplify his calculations using the wavenumber (the number of waves occupying the unit length, equal to 1/λ, the inverse of the wavelength) as his unit of measurement.

  6. Hydrogen atom - Wikipedia

    en.wikipedia.org/wiki/Hydrogen_atom

    The exact value of the Rydberg constant assumes that the nucleus is infinitely massive with respect to the electron. For hydrogen-1, hydrogen-2 ( deuterium ), and hydrogen-3 ( tritium ) which have finite mass, the constant must be slightly modified to use the reduced mass of the system, rather than simply the mass of the electron.

  7. Composition of the human body - Wikipedia

    en.wikipedia.org/wiki/Composition_of_the_human_body

    Parts-per-million cube of relative abundance by mass of elements in an average adult human body down to 1 ppm. About 99% of the mass of the human body is made up of six elements: oxygen, carbon, hydrogen, nitrogen, calcium, and phosphorus. Only about 0.85% is composed of another five elements: potassium, sulfur, sodium, chlorine, and magnesium ...

  8. Rydberg - Wikipedia

    en.wikipedia.org/wiki/Rydberg

    Jan Rydberg, (1923-2015), Swedish chemist who worked on nuclear chemistry and recycling at Chalmers University of Technology; Johannes Rydberg (1854–1919), Swedish physicist and deviser of the Rydberg formula; Kaisu-Mirjami Rydberg (1905–1959), Finnish journalist and politician; Per Axel Rydberg (1860–1931), Swedish-American botanist

  9. Talk:Rydberg constant - Wikipedia

    en.wikipedia.org/wiki/Talk:Rydberg_constant

    As the formula for the Rydberg constant contains no less than five other physical constants, namely the elementary charge , the electron rest mass , the permittivity of vacuum , reduced Planck's constant , and the speed of light in vacuum , it is one of the most well-determined physical constants. Measuring the Rydberg constant confirms the ...