1 / 24

Chapter 28 The Atom

Chapter 28 The Atom. Objectives. 28.1 Explain the structure of the atom 28.1 Distinguish continuous spectra from a line spectra 28.1 Contrast emission and absorption spectra 28.1 Solve problems using the orbital radius and energy level equations. Objectives.

phiala
Download Presentation

Chapter 28 The Atom

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. Chapter 28 The Atom

  2. Objectives • 28.1Explain the structure of the atom • 28.1 Distinguish continuous spectra from a line spectra • 28.1 Contrast emission and absorption spectra • 28.1 Solve problems using the orbital radius and energy level equations

  3. Objectives • 28.2Describe the shortcomings of the Bohr model of the atom • 28.2 Describe the quantum model of the atom • 28.2 Explain how a laser works and describe properties of laser light

  4. Different Models of the Atom • Dalton: Billiard Ball • Indivisable • J.J. Thomson • Plum Pudding Model • Rutherford • The Nuclear Model (Positive nucleus with orbiting electrons) • Others have built on this model

  5. Some Terms • Alpha Particle: Helium Particle with a positive charge • Emission Spectrum: Wavelengths emitted by an atom is called its • Absorption Spectrum: Same idea, but what wavelengths are absorbed • Spectroscope: Used to determine the wavelengths of visible light given off

  6. Continuous Spectrum produced by having very hot objects • A theoretical black body produces a continuous spectrum

  7. Spectroscopy: Identifying elements by their emission spectrum or absorption spectrum

  8. Red Shift: Moving Away Blue Shift: Moving Towards

  9. Rutherford vs Bohr • Rutherford: Electrons orbit like a planet orbits a star (Planetary model of the atom) • Issues: Falling into nucleus, radiating all wavelengths

  10. Bohr Model • Energy Quantized: Electrons only fall when giving off energy • Falls and jumps correspond to certain energies

  11. Terms • Energy Levels: Refers to the orbital's around the nucleus (Noted as n = 1, n = 2). Also called the Quantum Numbers • Ground State: When an electron has the lowest energy level allowed • Excited State: When an electron has absorbed energy and has moved to a higher orbital. Don’t last long (nanoseconds) at the level before falling

  12. From Last Chapter • hf (energy emitted) = Eexcited – Eground

  13. What wavelength of light is required to make hydrogen’s electron jump from n = 1 to • N = 2 • N = 3 • N = 4

  14. Elements beyond Hydrogen • Require different amounts of ionization energy (Graph shows outside electron) • Top Right

  15. Atom Size • Large = More Lines • Uranium on Bottom • Hydrogen on Top

  16. Molecules verse Atoms • Would also have a much larger range of emission lines and spectra

  17. How many eV’s required for Helium’s 588nm emission? How many eV’s required for Heliums 402nm emission?

  18. How much energy between shells? • Follows (1/n2) • If the n = 1 is equal to – 16 eV, how many eV of energy does a • N = 2 electron have? • - 16 eV x (1/22) = - 4 eV • N = 4 electron have? • How much energy is released going from N = 4 to N = 2? What wavelength is that?

  19. Back to Waves • Electron Cloud: Represents a high (90%) probability of finding an electron • Quantum Mechanics: The Study of the properties of matter using its wave properties • Coherent Light: When waves of light are in sync with one another, maxima and minima lining up

  20. Lasers • Create Coherent Light by Stimulated Emission • An electron in an excited state hit by a photon will fall releasing light in phase with the light that hit it

  21. Which is coherent?

More Related