1 / 8

Electrons Cathode Ray Tube Experiments Millikan oil-drop experiment Davy, Faraday, Stoney, Thomson

Fundamental Particles of Matter. Electrons Cathode Ray Tube Experiments Millikan oil-drop experiment Davy, Faraday, Stoney, Thomson Protons Cathode Ray Tube Experiments Rutheford scattering experiment Neutrons  -Bombardment experiments Chadwick. Cathode rays

wharton
Download Presentation

Electrons Cathode Ray Tube Experiments Millikan oil-drop experiment Davy, Faraday, Stoney, Thomson

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. Fundamental Particles of Matter • Electrons • Cathode Ray Tube Experiments • Millikan oil-drop experiment • Davy, Faraday, Stoney, Thomson • Protons • Cathode Ray Tube Experiments • Rutheford scattering experiment • Neutrons • -Bombardment experiments • Chadwick

  2. Cathode rays • Travel in straight lines • Negatively charged • Have mass • Cathode rays = Electron beam • Thomson determined the e/m ratio by studying the deflection of the beam in electric and magnetic fields

  3. Millikan Drop analysis • Determined the charge (e) on an electron from the experiment • e/m = 1.75882*108 C/g from the cathode ray exp. • m = 1.75882*108 C/g * e = 9.10940*10-28 g

  4. Original “Plum Pudding” Model • Protons • Cathode Ray Tube Experiments • Atom  cation+ + e- • Canal Rays = Positive (cation) rays • H2 2H+ + 2e- • Determined the e/m of a proton • Rutheford Scattering Experiment • Nucleus New Model

  5. Atomic Number • Moseley • Bombarded Elements with high energy e- • Produced different wavelengths for different element • Each element differs from the preceding element by having one more proton • An atom is defined by the # of protons

  6. Isotopes - Atoms of the same element (have the same # of protons) that have different masses (have differing number of neutrons) • Mass number A = Z (#p) + #n Nuclide Symbol E A Z 11 5 10 5 #n=6 #n=5 B B

  7. Mass Spectrometry - measures the charge-to-mass (e/m) ratio of charged particles. If we put Neon in a mass spectrometer we could determine how many natural isotopes there are for neon and the percent abundance of each isotope 20Ne 90.48% 21Ne 0.27% 22Ne 9.25% atomic mass of Ne = 19.99244*0.9048 + 20.99384*0.0027 + 20.99384*0.925 atomic mass Ne = 20.1979 amu

More Related