NationMaster - Encyclopedia: Rydberg constant

The Rydberg constant, named after physicist Janne Rydberg, is a physical constant discovered when measuring the spectrum of hydrogen, and building upon results from Anders Jonas Ångström and Johann Balmer. Each chemical element has its own Rydberg constant, which can be derived from the "infinity" Rydberg constant. A physicist is a scientist trained in physics. ... Janne Rydberg Johannes Robert Rydberg, commonly known as Janne Rydberg, (November 8, 1854 - December 28, 1919), was a Swedish physicist mainly known for devising the Rydberg formula, in 1888, which is used to predict the wavelengths of photons (of light and other electromagnetic radiation) emitted by changes in the energy... In science, a physical constant is a physical quantity whose numerical value does not change. ... The visible spectrum is the portion of the optical spectrum (light or electromagnetic spectrum) that is visible to the human eye. ... General Name, Symbol, Number hydrogen, H, 1 Chemical series nonmetals Group, Period, Block 1, 1, s Appearance colorless Atomic mass 1. ... Anders Jonas Ã…ngstrÃ¶m Anders Jonas Ã…ngstrÃ¶m (August 13, 1814 â€“ June 21, 1874) was a physicist in Sweden, one of the founders of the science of spectroscopy. ... Johann Jakob Balmer (May 1, 1825 – March 12, 1898) was a Swiss mathematician. ... A chemical element, often called simply element, is a chemical substance that cannot be divided or changed into other chemical substances by any ordinary chemical technique. ...

The "infinity" Rydberg constant is (according to 2002 CODATA results): CODATA (Committee on Data for Science and Technology) was established in 1966 as an interdisciplinary committee of the International Council of Science (ICSU), formerly the International Council of Scientific Unions. ...

$R_infty = 1.0973731568525(73) cdot 10^7 ,mathrm{m}^{-1}$

This constant is often used in atomic physics in the form of an energy: Atomic physics (or atom physics) is the field of physics that studies atoms as isolated systems comprised of electrons and atomic nuclei. ...

$h c R_infty = 13.6056923(12) ,mathrm{eV} equiv 1 ,mathrm{Ry}$

The "infinity" constant appears in the formula:

$R_M = frac{R_infty}{1+frac{m_e}{M}}$

which gives the Rydberg constant for a certain atom with one electron with the rest mass $m_e$ and the atomic nucleus mass $M$ . It can be derived from the formula: Properties In chemistry and physics, an atom (Greek Î¬Ï„Î¿Î¼Î¿Î½ meaning indivisible) is the smallest possible particle of a chemical element that retains its chemical properties. ... Properties The electron is a fundamental subatomic particle that carries a negative electric charge. ... The term mass in special relativity is used in a couple of different ways, occasionally leading to a great deal of confusion. ... A stylized Bohr model-like representation of a lithium atom. ...

$R_infty = frac{m_e e^4}{(4 pi epsilon_0)^2 hbar^3 2 pi c}$

where

$hbar$ is the reduced Planck's constant,

$m_e$ is the rest mass of the electron,

$e$ is the elementary charge,

$c$ is the speed of light in vacuum, and

$epsilon_0$ is the permittivity of free space.

The Rydberg constant is one of the most well-determined physical constants with a relative experimental uncertainty of less than 7 parts per trillion. The ability to measure the Rydberg constant directly to such a high precision confirms the proportions of the values of the other physical constants that define it. A commemoration plaque for Max Planck on his discovery of Plancks constant, in front of Humboldt University, Berlin. ... The term mass in special relativity is used in a couple of different ways, occasionally leading to a great deal of confusion. ... Properties The electron is a fundamental subatomic particle that carries a negative electric charge. ... The elementary charge (symbol e or sometimes q) is the electric charge carried by a single proton, or equivalently, the negative of the electric charge carried by a single electron. ... Cherenkov effect in a swimming pool nuclear reactor. ... Look up Vacuum in Wiktionary, the free dictionary For other uses, see vacuum (disambiguation) A vacuum is a volume of space that is empty of matter, including air, so that gaseous pressure is much less than standard atmospheric pressure. ... This article is in need of attention. ...

The Rydberg constant can also be expressed as the following equations.

$R_infty = frac{alpha^2 m_e c}{4 pi hbar} = frac{alpha^2}{2 lambda_e}$

where

$alpha$ is the fine-structure constant, and

$lambda_e$ is the Compton wavelength of the electron.

The fine-structure constant or Sommerfeld fine-structure constant, usually denoted , is the fundamental physical constant characterizing the strength of the electromagnetic interaction. ... The Compton wavelength of a particle is given by , where is the Planck constant, is the particles mass and is the speed of light. ...

Rydberg Constant for H

Plugging in the rest mass of an electron and an atomic mass $M$ of 1 for hydrogen, we find the Rydberg constant for hydrogen, $R H$ .

$R_H = 10967758 pm 1 m^{-1}$

Plugging this constant into the Rydberg formula, we can obtain the emission spectrum of hydrogen. The Rydberg formula (Rydberg-Ritz formula) is used in atomic physics for determining the full spectrum of light emission from hydrogen, later extended to be useful with any element. ...

Rydberg constant - Wikipedia, the free encyclopedia (232 words)
	The Rydberg constant, named after physicist Janne Rydberg, is a physical constant discovered when measuring the spectrum of hydrogen, and building upon results from Anders Jonas Ångström and Johann Balmer.
	The Rydberg constant is one of the most well-determined physical constants with a relative experimental uncertainty of less than 7 parts per trillion.
	The ability to measure the Rydberg constant directly to such a high precision confirms the proportions of the values of the other physical constants that define it.

Rydberg Transitions (1715 words)
	Rydberg transitions may be split by core asymmetries, but the splittings decrease with increasing n because the core becomes better modeled as a point charge as the electron radius increases.
	The oscillator strength of the lowest Rydberg transition in a series never exceeds 0.08 per degree of degeneracy, whereas for valence shell transitions values of 0.3-1.0 are easy to achieve (the V state transition in ethylene has 0.34).
	Rydberg excitations beyond the first ionization potential are typically broadened by autoionization and appear as a broad band on the continuum.

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