Bohr atomic model

Bohr atomic model

 description of the structure of atoms, especially that of hydrogen, proposed (1913) by the Danish physicist Niels Bohr (Bohr, Niels). The Bohr model of the atom, a radical departure from earlier, classical descriptions, was the first that incorporated quantum theory and was the predecessor of wholly quantum-mechanical models. The Bohr model and all of its successors describe the properties of atomic electrons in terms of a set of allowed (possible) values. Atoms absorb or emit radiation only when the electrons abruptly jump between allowed, or stationary, states. Direct experimental evidence for the existence of such discrete states was obtained (1914) by the German-born physicists James Franck (Franck, James) and Gustav Hertz (Hertz, Gustav).

      Immediately before 1913, an atom was thought of as consisting of a tiny positively charged heavy core, called a nucleus, surrounded by light, planetary negative electrons revolving in circular orbits of arbitrary radii.

      Bohr amended that view of the motion of the planetary electrons to bring the model in line with the regular patterns (spectral series) of light emitted by real hydrogen atoms. By limiting the orbiting electrons to a series of circular orbits having discrete radii, Bohr could account for the series of discrete wavelengths in the emission spectrum of hydrogen. Light, he proposed, radiated from hydrogen atoms only when an electron made a transition from an outer orbit to one closer to the nucleus. The energy lost by the electron in the abrupt transition is precisely the same as the energy of the quantum of emitted light.

* * *


Universalium. 2010.

Игры ⚽ Нужно сделать НИР?

Look at other dictionaries:

  • Rutherford atomic model —  description of the structure of atoms proposed (1911) by the British physicist Ernest Rutherford (Rutherford, Ernest, Baron Rutherford of Nelson, of Cambridge). The model described the atom as a tiny, dense, positively charged core called a… …   Universalium

  • Bohr, Niels — ▪ Danish physicist Introduction in full  Niels Henrik David Bohr  born Oct. 7, 1885, Copenhagen, Den. died Nov. 18, 1962, Copenhagen  Danish physicist who was the first to apply the quantum theory, which restricts the energy of a system to… …   Universalium

  • Atomic orbital model — The Atomic Orbital Model is the currently accepted model of the electrons in an atom. It is sometimes called the Wave Mechanics Model. In the atomic orbital model, the atom consists of a nucleus surrounded by orbiting electrons. These electrons… …   Wikipedia

  • Atomic theory — Atomic model redirects here. For the unrelated term in mathematical logic, see Atomic model (mathematical logic). This article is about the historical models of the atom. For a history of the study of how atoms combine to form molecules, see… …   Wikipedia

  • Atomic physics — (or atom physics) is the field of physics that studies atoms as an isolated system of electrons and an atomic nucleus. It is primarily concerned with the arrangement of electrons around the nucleus and the processes by which these arrangements… …   Wikipedia

  • Atomic orbital — The shapes of the first five atomic orbitals: 1s, 2s, 2px, 2py, and 2pz. The colors show the wave function phase. These are graphs of ψ(x,y,z) functions which depend on the coordinates of one electron. To see the elongated shape of ψ(x,y,z)2… …   Wikipedia

  • Bohr model — In atomic physics, the Bohr model created by Niels Bohr depicts the atom as a small, positively charged nucleus surrounded by electrons that travel in circular orbits around the nucleus mdash;similar in structure to the solar system, but with… …   Wikipedia

  • Bohr — can refer to any of the following Danish people:* Niels Bohr (1885 1962), Danish atomic physicist, Nobel Prize in physics 1922 * Aage Niels Bohr (born 1922), Danish nuclear physicist, Nobel Prize in physics 1975, son of Niels Bohr * Christian… …   Wikipedia

  • shell nuclear model — ▪ physics       description of nuclei of atoms by analogy with the Bohr atomic model of electron energy levels. It was developed independently in the late 1940s by the American physicist Maria Goeppert Mayer (Mayer, Maria Goeppert) and the German …   Universalium

  • Bohr , Niels Hendrik David — (1885–1962) Danish physicist Niels Bohr came from a very distinguished scientific family in Copenhagen, Denmark. His father, Christian, was professor of physiology at Copenhagen and his brother Harald was a mathematician of great distinction.… …   Scientists

Share the article and excerpts

Direct link
… Do a right-click on the link above
and select “Copy Link”