Movatterモバイル変換


[0]ホーム

URL:


Encyclopedia Britannica
Encyclopedia Britannica
SUBSCRIBE
SUBSCRIBE
SUBSCRIBE
History & SocietyScience & TechBiographiesAnimals & NatureGeography & TravelArts & Culture
Ask the ChatbotGames & QuizzesHistory & SocietyScience & TechBiographiesAnimals & NatureGeography & TravelArts & CultureProConMoneyVideos
Bohr atomic model of a nitrogen atom
Bohr atomic model of a nitrogen atomBohr atomic model of a nitrogen atom. The central nucleus contains the protons and neutrons, while the electrons are found outside the nucleus.

Bohr model

physics
verifiedCite
While every effort has been made to follow citation style rules, there may be some discrepancies.Please refer to the appropriate style manual or other sources if you have any questions.
Select Citation Style
Feedback
Corrections? Updates? Omissions? Let us know if you have suggestions to improve this article (requires login).
Thank you for your feedback

Our editors will review what you’ve submitted and determine whether to revise the article.

Also known as: Bohr atomic model, Bohr theory
Key People:
Niels Bohr
Related Topics:
atom

Bohr model, description of the structure ofatoms, especially that ofhydrogen, proposed (1913) by the Danish physicistNiels Bohr. The Bohrmodel of the atom, a radical departure from earlier, classical descriptions, was the first that incorporatedquantum theory and was thepredecessor of whollyquantum-mechanical models. The Bohr model and all of its successors describe the properties of atomicelectrons 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 physicistsJames Franck andGustav Hertz.

Immediately before 1913, theRutherford model conceived of an atom 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.

Niels Bohr's contribution to atomic theory explainedAn overview of Niels Bohr's refinement of the Rutherford model.
See all videos for this article
Bohr model of the atomIn the Bohr model of the atom, electrons travel in defined circular orbits around the nucleus. The orbits are labeled by an integer, the quantum numbern. Electrons can jump from one orbit to another by emitting or absorbing energy. The inset shows an electron jumping from orbitn=3 to orbitn=2, emitting a photon of red light with an energy of 1.89 eV.

Bohramended 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 realhydrogen 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 anelectron 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 thequantum of emitted light.

Encyclopaedia Britannica thistle graphic to be used with a Mendel/Consumer quiz in place of a photograph.
Britannica Quiz
Matter and More Quiz
The Editors of Encyclopaedia BritannicaThis article was most recently revised and updated byMelissa Petruzzello.

[8]
ページ先頭

©2009-2025 Movatter.jp