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  2. History of atomic theory - Wikipedia

    en.wikipedia.org/wiki/History_of_atomic_theory

    The current theoretical model of the atom involves a dense nucleus surrounded by a probabilistic "cloud" of electrons. Atomic theory is the scientific theory that matter is composed of particles called atoms. The definition of the word "atom" has changed over the years in response to scientific discoveries.

  3. Atomic physics - Wikipedia

    en.wikipedia.org/wiki/Atomic_physics

    Bohr Model of the Atom. The Bohr model, proposed by Niels Bohr in 1913, is a revolutionary theory describing the structure of the hydrogen atom. It introduced the idea of quantized orbits for electrons, combining classical and quantum physics. Key Postulates of the Bohr Model. 1.Electrons Move in Circular Orbits:

  4. Bohr model - Wikipedia

    en.wikipedia.org/wiki/Bohr_model

    The Bohr model is a relatively primitive model of the hydrogen atom, compared to the valence shell model. As a theory, it can be derived as a first-order approximation of the hydrogen atom using the broader and much more accurate quantum mechanics and thus may be considered to be an obsolete scientific theory .

  5. Atom - Wikipedia

    en.wikipedia.org/wiki/Atom

    The Bohr model of the atom, with an electron making instantaneous "quantum leaps" from one orbit to another with gain or loss of energy. This model of electrons in orbits is obsolete. A problem in classical mechanics is that an accelerating charged particle radiates electromagnetic radiation, causing the particle to lose kinetic energy.

  6. Niels Bohr - Wikipedia

    en.wikipedia.org/wiki/Niels_Bohr

    [170] [171] On 7 October 2012, in celebration of Niels Bohr's 127th birthday, a Google Doodle depicting the Bohr model of the hydrogen atom appeared on Google's home page. [172] An asteroid, 3948 Bohr , was named after him, [ 173 ] as was the Bohr lunar crater , and bohrium , the chemical element with atomic number 107, in acknowledgement of ...

  7. Plum pudding model - Wikipedia

    en.wikipedia.org/wiki/Plum_pudding_model

    The plum pudding model was the first scientific model of the atom to describe an internal structure. It was first proposed by J. J. Thomson in 1904 following his discovery of the electron in 1897, and was rendered obsolete by Ernest Rutherford 's discovery of the atomic nucleus in 1911.

  8. Bohr–Sommerfeld model - Wikipedia

    en.wikipedia.org/wiki/Bohr–Sommerfeld_model

    Orbitals of the Radium. (End plates to [1]) 5 electrons with the same principal and auxiliary quantum numbers, orbiting in sync. ([2] page 364) The Sommerfeld extensions of the 1913 solar system Bohr model of the hydrogen atom showing the addition of elliptical orbits to explain spectral fine structure.

  9. Rutherford model - Wikipedia

    en.wikipedia.org/wiki/Rutherford_model

    The Rutherford model is a name for the first model of an atom with a compact nucleus. The concept arose from Ernest Rutherford discovery of the nucleus. Rutherford directed the Geiger–Marsden experiment in 1909, which showed much more alpha particle recoil than J. J. Thomson's plum pudding model of the atom could explain. Thomson's model had ...