1. The Periodic Table Ms. Pollock Physical Science 2008-2009

2. Organizing the Elements Dmitri Mendeleev’s periodic table published in 1869 in RussiaDmitri Mendeleev’s periodic table published in 1869 in Russia Born in Siberia in 1834Born in Siberia in 1834 Chemistry professor at University of St. PetersburgChemistry professor at University of St. Petersburg Wrote textbook for students; led to development of periodic tableWrote textbook for students; led to development of periodic table Extremely accurate periodic table for timeExtremely accurate periodic table for time

3. Dmitri Ivanovich Mendeleev http://www.aip.org/hist ory/curie/periodic.htm

4. Mendeleev’s Table Just over 60 elements identified at the timeJust over 60 elements identified at the time Organized by atomic weights (masses) and found that the properties of elements repeated periodicallyOrganized by atomic weights (masses) and found that the properties of elements repeated periodically Not all elements known, so some spaces left blankNot all elements known, so some spaces left blank Accurately predicted properties of elements not yet discoveredAccurately predicted properties of elements not yet discovered

5. Mendeleev’s Table

6. Improving the Periodic Table Henry Moseley, 1913Henry Moseley, 1913 Found that some elements did not line up perfectly in Mendeleev’s tableFound that some elements did not line up perfectly in Mendeleev’s table Re-ordered elements by atomic number, rather than atomic massRe-ordered elements by atomic number, rather than atomic mass British; studied with Ernest RutherfordBritish; studied with Ernest Rutherford Killed in World War IKilled in World War I

7. Henry Moseley http://www.chemistry.c o.nz/henry_moseley.htm

8. The Atom and the Periodic Table Elements sorted according to propertiesElements sorted according to properties Groups – vertical columns; similar propertiesGroups – vertical columns; similar properties –Same group = electrons in same energy level –Electrons in same energy level = similar chemical properties and behavior Periods – horizontal rowsPeriods – horizontal rows –Each row a new energy level –Row 1 = 1 energy level –Row 7 = 7 energy levels

9. The Atom and the Periodic Table

10. Electron Dot Diagrams Elements in same group have the same number of electrons in their outer energy levels.Elements in same group have the same number of electrons in their outer energy levels. The outer energy level can be drawn using an electron dot diagram.The outer energy level can be drawn using an electron dot diagram. The symbol of the element and a series of dots are used to represent electrons in the outer energy levels.The symbol of the element and a series of dots are used to represent electrons in the outer energy levels. Developed by American chemist G. N. LewisDeveloped by American chemist G. N. Lewis

11. Electron Dot Diagrams http://www.ausetute.com.au/lewisstr.htmlhttp://www.ausetute.com.au/lewisstr.htmlhttp://www.ausetute.com.au/lewisstr.html Write the symbol first.Write the symbol first. Then, place one electron at each side of the symbol.Then, place one electron at each side of the symbol. Finally, pair electrons until all valence (outer shell) electrons are accounted for.Finally, pair electrons until all valence (outer shell) electrons are accounted for.

12. Electron Dot Diagrams Cl Group 17: Valence electrons cannot exceed 8 (octet rule), so take the group number (17) and subtract 10. 17 – 10 = 7 valence electrons

13. Electron Dot Diagrams Cl

14. Electron Dot Diagrams Cl

15. Electron Dot Diagrams Cl

16. Electron Dot Diagrams Cl

17. Electron Dot Diagrams Cl

18. Electron Dot Diagrams Cl

19. Electron Dot Diagrams Cl

20. Regions on the Periodic Table Several areas on periodic table with specific namesSeveral areas on periodic table with specific names Left = metals (mostly solids)Left = metals (mostly solids) Right = nonmetals (mostly gases)Right = nonmetals (mostly gases) Zig-zag line = metalloidsZig-zag line = metalloids Extra rows = Lanthanides and ActinidesExtra rows = Lanthanides and Actinides

21. Periodic Table Regions (Metals) http://www.dkimages.com/discover/previews/796/939317.JPG

22. Periodic Table Regions (Nonmetals)

23. Periodic Table Regions (Metalloids) katie-maggie-mettaloids-g.wikispaces.com

24. Elements in the Universe Modern technology making elements in other parts of universe easy to identifyModern technology making elements in other parts of universe easy to identify Hydrogen and helium thought building blocks of other elementsHydrogen and helium thought building blocks of other elements Many elements found only in stars or as a result of the decay of other elementsMany elements found only in stars or as a result of the decay of other elements

25. http://images.iop.org/objects/physicsweb/world/16/7/3/pwpia1_07-03.jpg