1 / 22

Bohr’s Third Postulate

This article delves into Bohr’s third postulate regarding electron transitions and photon emission, explaining how these concepts relate to the characteristics of stars, such as color and temperature. It further examines the assumption made by Bohr regarding the non-radiation of electrons in specified orbits. We then explore the wave nature of matter through de Broglie wavelengths and the implications of the wave function in quantum mechanics, discussing the probabilistic nature of particle behavior and the Heisenberg Uncertainty Principle. This foundation leads to important questions regarding radiation in everyday objects and photon interactions.

quang
Télécharger la présentation

Bohr’s Third Postulate

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Bohr’s Third Postulate A single photon is emitted whenever an electron jumps down from one orbit to another.

  2. Why do astronomers often use the terms color and temperature interchangeably when referring to stars? • Why did Bohr assume that the electrons do not radiate when they are in the allowed orbits?

  3. Wave Nature of Matter

  4. De Broglie Wavelength

  5. Wave-particle duality apply also to matter.

  6. De Broglie’s Hypothesis Applied to Atoms

  7. Quantum Mechanics of Atoms

  8. The Wave Function and Its Interpolation

  9. In quantum mechanics the amplitude of a particle wave is called the wave function and is given the symbol Y.

  10. If we are dealing only with one photon: At any point the square of the electric field strength is a measure of the probability that a photon will be at that location.

  11. For a single particle: Y2 at a certain point in space and time represents the probability of finding the electron at the given position and time.

  12. Important: there is no way to predict where one electron would hit the screen. We could predict only probabilities.

  13. The main point of this discussion is this: if we treat electrons as if they were waves, then Y represents the wave amplitude. If we treat them as particles, then we must treat them on probabilistic basis.

  14. The Heisenberg Uncertainty Principle

  15. The act of observing produces a significant uncertainty in either the position or the momentum of electron.

  16. Position uncertainty of a baseball What is the uncertainty in position, imposed by the uncertainty principle, of a 150-g baseball thrown at 42+-1 m/s? Should the umpire be concerned? Can he use Heisenberg as an excuse?

  17. Particle in a Box

  18. Baby-Quiz • If all objects emit radiation, why don’t we see most of them in the dark? • Suppose you were a nineteenth-century scientist who had just discovered a new phenomenon known as Zeta rays. What experiment could you perform to define if Zeta rays are charged particles or e/m waves? Could this experiment distinguish between neutral particles and an e/m wave? • If a metal surface is illuminated by light at a single frequency, why don’t all the photoelectrons have the same kinetic energy when they leave the metal’s surface? • What property of the emitted electrons depends on the intensity of incident light?What property of the emitted photoelectrons depends on the frequency of incident light?

More Related