Periodic Law


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Periodic Law

  1. 1. Chapter 5
  2. 2. The Periodic Table
  3. 3. History of Periodic Table <ul><li>1860 </li></ul><ul><ul><li>More than 60 elements had been discovered </li></ul></ul><ul><ul><li>No accurate method to determine atomic mass or the number of atoms of element in compounds </li></ul></ul><ul><ul><li>Different chemists used different values for the same elements </li></ul></ul><ul><li>September of 1860 </li></ul><ul><ul><li>First International Congress of Chemists </li></ul></ul><ul><ul><li>Cannizzaro (Italian) presented method for measuring atomic masses of atoms </li></ul></ul><ul><ul><ul><li>Enabled chemists to agree on standard values for atomic mass </li></ul></ul></ul>
  4. 4. History Continued… <ul><li>Mendeleev </li></ul><ul><ul><li>Russian Chemist </li></ul></ul><ul><ul><li>Wanted to organize elements according to properties </li></ul></ul><ul><ul><li>Created first periodic table based on similarities </li></ul></ul><ul><ul><li>Left many spaces due to his process of organization </li></ul></ul>
  5. 5. History Continued… <ul><li>Moseley </li></ul><ul><ul><li>Worked with Rutherford </li></ul></ul><ul><ul><li>Discovered a previously unrecognized pattern </li></ul></ul><ul><ul><li>Work led to modern definition of atomic number and this is the basis for organization of table </li></ul></ul><ul><ul><li>Consistent with Mendeleev’s ordering of table </li></ul></ul>
  6. 6. Periodic Law <ul><li>Based on Mendeleev’s principle of chemical periodicity </li></ul><ul><li>The physical and chemical properties of the elements are periodic functions of their atomic numbers. </li></ul>
  7. 7. Periodic Law <ul><li>In simple terms: </li></ul><ul><ul><li>When the elements are arranged in order of increasing atomic number, elements with similar properties appear at regular intervals </li></ul></ul>
  8. 8. Modern Periodic Table <ul><li>Noble Gases </li></ul><ul><ul><li>First was discovered in 1868 </li></ul></ul><ul><ul><li>Helium </li></ul></ul><ul><ul><ul><li>Discovered as a component of the sun </li></ul></ul></ul>
  9. 9. Modern Periodic Table <ul><li>Lanthanides </li></ul><ul><ul><li>The 14 elements with atomic numbers from 58 (Cerium) to 71 (Lutetium) </li></ul></ul><ul><ul><li>Belong to the </li></ul></ul><ul><ul><li>6 th period </li></ul></ul>
  10. 10. Modern Periodic Table <ul><li>Actinides </li></ul><ul><li>The 14 elements with atomic numbers 90 (Thorium) to 103 (Lawrencium) </li></ul><ul><li>Belong to the 7th period </li></ul>
  11. 11. 5.2: Electron Configuration & The Periodic Table <ul><li>Periods </li></ul><ul><ul><li>Horizontal rows on the periodic table </li></ul></ul><ul><ul><li>Identifies energy level of element </li></ul></ul>
  12. 12. Electron Configuration and Periodic Table <ul><li>Groups/Families </li></ul><ul><ul><li>Vertical columns on table </li></ul></ul><ul><ul><li>Identifies number of valence electrons </li></ul></ul>
  13. 13. Group 1 <ul><li>Group 1 (Alkali Metals) </li></ul><ul><ul><li>Silvery appearance </li></ul></ul><ul><ul><li>Soft enough to cut with a knife </li></ul></ul><ul><ul><li>Extremely reactive </li></ul></ul><ul><ul><li>Not found in nature as free elements </li></ul></ul><ul><ul><li>Melt at low temperatures </li></ul></ul>
  14. 14. Group 2 <ul><li>Alkaline-Earth Metals </li></ul><ul><ul><li>Harder </li></ul></ul><ul><ul><li>Denser </li></ul></ul><ul><ul><li>Stronger </li></ul></ul><ul><ul><li>Slightly less reactive </li></ul></ul><ul><ul><li>Not found in nature as free elements </li></ul></ul>
  15. 15. Groups 3 - 12 <ul><li>Transition Elements </li></ul><ul><ul><li>Good conductors of electricity </li></ul></ul><ul><ul><li>High luster </li></ul></ul><ul><ul><li>Some do not form compounds easily </li></ul></ul><ul><ul><li>Exist in nature as free elements </li></ul></ul>
  16. 16. Group 17 <ul><li>Halogens </li></ul><ul><ul><li>React with most metals to form salts </li></ul></ul><ul><ul><li>7 electrons in outer shell </li></ul></ul><ul><ul><li>Exist at room temperature in all three states of matter </li></ul></ul>
  17. 17. Group 18 <ul><li>Noble Gases </li></ul><ul><ul><li>Inert gases </li></ul></ul><ul><ul><li>Relatively nonreactive </li></ul></ul><ul><ul><li>Have a complete valence shell </li></ul></ul><ul><ul><li>Low boiling points </li></ul></ul><ul><ul><li>All are gases at room temperature </li></ul></ul>
  18. 18. Periodic Properties <ul><li>Arranged on periodic table according to atomic number </li></ul><ul><li>However, that isn’t all! </li></ul>
  19. 19. Periodic Properties <ul><li>Atomic Radii </li></ul><ul><li>Ionization Energy </li></ul><ul><li>Electron Affinity </li></ul><ul><li>Ionic Radii </li></ul><ul><li>Electronegativity </li></ul>
  20. 20. Cited Sources: <ul><li>Photo of Mendeleev </li></ul><ul><ul><li> </li></ul></ul><ul><li>Photo of Moseley </li></ul><ul><ul><li> </li></ul></ul><ul><li>Lanthanide series </li></ul><ul><ul><li> </li></ul></ul><ul><li>Noble gases </li></ul><ul><ul><li> </li></ul></ul><ul><li>Actinide series </li></ul><ul><ul><li> </li></ul></ul><ul><li>Halogen Group </li></ul><ul><ul><li>http:// </li></ul></ul><ul><li>Periods </li></ul><ul><ul><li> </li></ul></ul><ul><li>Groups/Families </li></ul><ul><ul><li> </li></ul></ul><ul><li>Alkali Metals </li></ul><ul><ul><li> </li></ul></ul>
  21. 21. Cited Sources Continued…. <ul><li>Alkaline-Earth Metals </li></ul><ul><ul><li>http:// </li></ul></ul><ul><li>Transition Elements </li></ul><ul><ul><li> </li></ul></ul><ul><li>Noble Gases </li></ul><ul><ul><li> </li></ul></ul><ul><li>Periodic Table </li></ul><ul><ul><li>http:// </li></ul></ul><ul><li>Periodic Table Video </li></ul><ul><ul><li>http:// </li></ul></ul>