1. The Periodic Table Chapter 6

2. A quest for accurate reproduction J.W. Dobereiner – published his triad classification system (ex. Cl,Br,I similar chemical properties) 1860 –Scientists agreed upon a method to measure mass –Are masses related to elemental properties? John Newlands –Noticed every 8 th element had similar properties –Law of octaves

3. The Law of Octaves

4. Dimitri Mendeleev - 1869 Organized the periodic table based on increasing atomic mass Predicted the properties of unknown elements –Sc, Ge, Ga P. 181 - Q 24, 25

6. Henry Moseley Arranged elements based on the number of protons Determined periodic law –Groups have similar properties –Properties change as you move across a period –Pattern repeats one period to the next P.181 - Q – 26, 27

8. Terminology Groups (Families) – (IUPAC labels 1-18) Periods Representative elements(1A – 8A) –Wide array of chemical and physical properties –Group number indicates number of valance electrons Transition elements Metalloids Metal Non metals P. 181 - Q - 31

9. Metals Shiny, smooth Good electrical and heat conductors Malleable, ductile Solid at room temp Reactive Alkali’s and Alkaline’s (s block)

10. Transition Metals D and F (Inner transitional metals) block Lanthanides and Actinides P. 181 - Q 33, 34, 35 – P. 182 – 48, 49, 53, 54

11. Non-Metals Most of p block gases or brittle solids (Br) Little luster Poor conductors Halogens very reactive Noble Gases (Inert Gases) - extremely unreactive due to filled s and p sublevels P. 181 – 28, 32

12. Metalloids Share properties of metals and non-metals Heavy step line – B, Si, Ge, As, Sb, Te, Po, At Found in p block P. 181 - 29

13. Atomic Radius Metals - Half the distance between adjacent nuclei in a crystal of an element. Non Metals - Half the distance between bonded atoms of the same element (diatomic molecule).

14. Atomic Radius – Family Trends Increases Atomic charge and occupied energy levels increase. Occupied orbitals shield electrons in the outer most energy level from the pull of the nucleus.

15. Atomic Radius – Period Trends decreases Increasing positive charge pulls the valence electrons closer to the nucleus. Shielding does not influence this trend because the effect is constant. P. 181 - Q - 36 - P. 182 - Q - 50

16. Ions – Atoms gain or lose electrons to have a complete set of valence electrons (Octet Rule) NaNa +1 11 protons 10 electrons 11 protons 11 electrons Empty outer orbital or energy level makes it smaller. Electrostatic repulsion decreases. 11 p  10 e

17. Increased electrostatic repulsion Cl 17 Protons 17 Electrons Cl 1- 17 Protons 18 Electrons

18. Ionic Radius – Family Trends Principle energy levels increase in size.

19. Ionic Radius – Period Trends 3 protons 2 electrons 4 protons 2 electrons 5 protons 2 electrons 6 protons 2 electrons 7 protons 10 electrons 8 protons 10 electrons 9 protons 10 electrons Electron repulsion decrease P. 181 - Q - 41, 42 - P. 182 - Q -52 - P. 183 - Q - 64, 65

20. Ionization Energy – energy needed for an atom to lose an electron Be  Be +  Be 2+  Be 3+ kilojoules/mol or kj/mol 1s 2 1s 2 1s 2 1s 1 2s 2 2s 1

21. 1 st ionization energies increase as you move across a period due to the increased attraction of the nuclear charge. The stability of the filled sub level affects the ionization energy. P. 181 – Q - 37, 38, 40 – P. 182 – Q – 55, 58 – P. 183 – Q – 67B

22. Ionization Energy – Family Trends Decreases as you move down a family. The further the electron from the nucleus the easier it is to remove. P. 181 - Q - 39

23. Electronegativity – a measure of an atom’s ability to attract an electron P. 181 - Q - 43, 44, 45