1 / 36

History

History. Ch. 5 - The Periodic Table. Mendeleev. Dmitri Mendeleev (1869, Russian) Organized by increasing atomic mass . Grouped by properties Some discrepancies . Mendeleev (continued). Dmitri Mendeleev (1869, Russian) Predicted properties of undiscovered elements. Moseley.

chance
Télécharger la présentation

History

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. History Ch. 5 - The Periodic Table

  2. Mendeleev • Dmitri Mendeleev (1869, Russian) • Organized by increasing atomic mass. • Grouped by properties • Some discrepancies.

  3. Mendeleev (continued) • Dmitri Mendeleev (1869, Russian) • Predicted properties of undiscovered elements.

  4. Moseley • Henry Moseley (1913, British) • Organized by increasing atomic number. • Resolved discrepancies in Mendeleev’s arrangement.

  5. Organization of theElements

  6. Metallic Character • Metals • Nonmetals • Metalloids

  7. Blocks Main group • s • p • d • f

  8. Chemical Reactivity • Families • Similar valence e- within a group result in similar chemical properties • They have similar valence configurations

  9. Chemical Reactivity • s1 • s2 • d-block • f-block • s2p5 • s2p6 • Alkali Metals • Alkaline Earth Metals • Transition metals • Inner transition metals • Halogens • Noble Gases

  10. Metallic Character

  11. Metallic Character

  12. Metallic Character

  13. Metallic Character

  14. Practice Choose from the following list of elements to answer the questions below: Gold (Au) Oxygen (O) Krypton (Kr) Silicon (Si) Magnesium (Mg) Iron (Fe) Boron (B) Sulfur (S) Which elements you would expect to be: Brittle: Sulfur, (Oxygen and Krypton would be if they were solid, but they’re both gases at room temperature) Malleable: Gold, Magnesium, Iron Conductive: Gold, Magnesium, Iron Somewhat brittle but somewhat malleable: Boron, Silicon Shiny: Gold, Magnesium, Iron Poor conductors: Sulfur, Oxygen, Krypton

  15. Practice Write the noble-gas notation for the electron configuration of calcium. In which period does it belong? Ca Noble gas notation: [Ar]4s2 Period: 4 [Ne]3s23p5 Element name: Chlorine Period: 3 Group number: 17 Metallic character: Nonmetal Block: p-block Group (family) name: halogens

  16. Determining number of Valence electrons • Same number as group number (subtract 10 for elements after d-block), or just count over from the beginning of the period on the periodic table (but skip d-block) How many valence electrons does each element have? N O S Al Cl K Mg 3 5 6 6 7 1 2

  17. Formation of Ions • An atom gains or loses electrons to reach a full shell • The number of electrons gained or lost determines the charge of the ion Lose electrons – Positive ion – CATION Gain electrons – Negative ion - ANION

  18. Periodic Trends Ch. 5 - The Periodic Table

  19. Periodic Law (Periodicity) • When elements are arranged in order of increasing atomic number, elements with similar properties appear at regular intervals.

  20. Chemical Reactivity • Alkali Metals • Alkaline Earth Metals • Transition metals • Halogens • Noble Gases

  21. Properties: • Atomic Radius Size of an atom • Electronegativity Ability of a bonded atom to attract electrons • Electron Affinity How much a neutral atom wants to gain an electron

  22. Atomic Radius • Atomic Radius K Na Li Ar Ne

  23. Atomic Radius • Atomic Radius – size of atom Increases to the LEFT and DOWN

  24. Atomic Radius • Why larger going down? • Higher energy levels have larger shells • Shielding - core e- block the attraction between the nucleus and the valence e- • Why smaller to the right? • Increased nuclear charge without additional shielding pulls e- in tighter

  25. Which atom has the larger radius? Why? • Be or Ba Ba: it has higher energy levels (larger shells), plus shielding • Ca or Br Ca: both are in the same energy level, but there is less nuclear charge for Ca, so electrons are not held as tightly

  26. Electron affinity • Electron affinity Increases UP and to the RIGHT, Does NOT include noble gases

  27. Which atom has the greater electron affinity? Why? • Na or F? F: It’s a smaller atom and holds electrons more strongly; nearly a full shell • O or Se O: smaller atom, attracts electrons more strongly

  28. Electronegativity • Atoms must be BONDED for electronegativity to be measured • Fluorine the most electronegative atom

  29. Electronegativity • Electronegativity Increases UP and to the RIGHT, Does NOT include noble gases

  30. Which atom has the greater electronegativity? Why? • Rb or F? F: Fluorine is THE most electronegative atom; small atom and nearly a full shell • S or P? S: smaller atom attracts electrons more strongly, shell closer to being full

  31. Ionic Radius • Cations Lose electrons - smaller • Anions Gain electrons – bigger

  32. Examples • Which particle has the larger radius? • S or S2- • Al or Al3+ S2- Al

More Related