Teoria y Estructura AtómicaTeoría Atómica: Bohr and the Beginnings of Quantum Theory

por Anthony Carpi, Ph.D., Adrian Dingle, Ph.D.

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Did you know that energy is not released in a continuous flow, but rather is released in “packets”? This discovery, known as quantum theory, changed the way we understand the basic properties of the atom. Many other advances in atomic theory were made in the 20th century, including the discovery of the neutron, which made the atom bomb possible.


The 20th century brought a major shift in our understanding of the atom, from the planetary model that Ernest Rutherford proposed to Niels Bohr’s application of quantum theory and waves to the behavior of electrons. With a focus on Bohr’s work, the developments explored in this module were based on the advancements of many scientists over time and laid the groundwork for future scientists to build upon further. The module also describes James Chadwick’s discovery of the neutron. Among other topics are anions, cations, and isotopes.

Términos que usted debe saber
  • anion = a negatively charged ion; an atom that has more electrons than protons
  • cation = a positively charged ion; an atom that has more protons than electrons
  • electronic = pertaining to electrons
  • emit = give off; send forth
  • spectrum (plural: spectra) = a continuing range such as of color or frequency; a series of colors arranged by wavelength as in a rainbow
Módulos de información de fondo

Figure 1: When passed through a prism, white light displays the color spectrum. image © NASA

Figure 2: The visible light spectrum is displayed at the top and line spectra for three elements - hydrogen, neon, and iron - are below. image © Neon spectrum: Deo Favente

Figure 3: Niels Bohr

Control de Comprensión

The planetary model of the atom was based on

Control de Comprensión

In an atom, the ground state is the orbital with the ______ potential energy.

Figure 4: Using the element hydrogen, examples of a cation and anion. image © Jkwchui

Control de Comprensión

_____ have a positive charge, while _____ have a negative charge.

Figure 5: Artistic model of an atom showing the nucleus, with protons and neutrons, and orbiting electrons. image © NASA

Control de Comprensión

A _____ is a heavy particle that has no charge.

Figure 6: Carbon isotopes. Each have the same number of protons, but different numbers of neutrons.

Control de Comprensión

Isotopes are atoms of the same element that have a different

Conceptos Clave

  • Drawing on experimental and theoretical evidence, Niels Bohr changed the paradigm of modern atomic theory from one that was based on physical particles and classical physics, to one based in quantum principles.
  • Under Bohr’s model of the atom, electrons cannot rotate freely around the atom, but are bound to certain atomic orbitals that both constrain and define an atoms electronic behavior.
  • Atoms can gain or lose electrons to become electrically charged ions.
  • James Chadwick completed the early picture of the atom with his discovery of the neutron, a neutral, nuclear particle that affects an atom’s mass and the different physical properties of atomic isotopes.

Lectura Adicional


Bohr, N. (1913). On the Constitution of Atoms and Molecules. Philosophical Magazine, Series 6 (London) 26: 1–25. Chadwick, J. (1932). The Possible Existence of a Neutron. Nature, 129(3252): 312. Dalton, John (1805). On the Absorption of Gases by Water and Other Liquids. Memoirs of the Literary and Philosophical Society of Manchester, 2nd ser.(1): 271–87. Einstein, A. (1905). A New Determination of Molecular Dimensions. Annalen der Physik, Series 4 19, 289–306. Einstein, A. (1905). Does the inertia of a body depend on its energy content? Annalen der Physik, Series 4 18, 639–641. Einstein, A. (1905). On the electrodynamics of moving bodies. Annalen der Physik, Series 4 17, 891–921. Einstein, A. (1905). On a heuristic viewpoint concerning the production and transformation of light. Annalen der Physik, Series 4 17, 132–148. Einstein, A. (1905). On the motion of small particles suspended in liquids at rest required by the molecular-kinetic theory of heat. Annalen der Physik, Series 4 19, 371–381. Planck, M. (1903). Treatise on Thermodynamics. Ogg, A. (trans.). London: Longmans, Green & Co.

Anthony Carpi, Ph.D., Adrian Dingle, Ph.D. “Teoría Atómica” Visionlearning Vol. CHE-1 (3), 2003.

Si alguien dice que puede pensar en problemas de cuántica sin emocionarse, eso solo muestro que no entiende nada acerca de ellos.
— Niels Bohr,