1. Chapter 6 The Periodic Table p. 154 The Elements by Tom Lehrer The Elements by Tom Lehrer

2. Organizing the Elements Chemists used elements properties to sort into groups. 1829 - J. W. Dobereiner  triads – groups of 3 w/ similar properties One element in triad had properties intermediate of other 2 elements Cl, Br, and I look different…. similar chemically

3. Mendeleev’s Periodic Table 1800s, about 70 elements known 1869 - Dmitri Mendeleev – Russian chemist & teacher Arranged elements by atomic mass

4. Mendeleev’s Periodic Table Blank spaces  undiscovered elements Predicted properties  predictions very accurate Problems w/ order  Te to I atomic mass decreases  I belongs w/ Br & Cl  Mendeleev broke rule – put Te before I

5. A better arrangement 1913, Henry Moseley  British physicist  Determined atomic #’s  Modern PT arranged by atomic #

6. The Elements by Tom Lehrer

7. Periodic Law Elements arranged by increasing atomic #, periodic repetition of properties present Horizontal rows = periods  7 periods Vertical column = group (family)  Similar properties  IUPAC labels (1-18) U.S. system (# & letter…i.e. IA, IIA)

8. Areas of periodic table 3 classes of elements:  1) Metals: electrical conductors, lustrous, ductile, malleable

9.  2) Nonmetals: generally brittle/non- lustrous, poor conductors of heat and electricity Some gases (O, N, Cl) some brittle solids (B, S) fuming red liquid (Br)

10.  3) Metalloids : border the line-2 sides  Properties are intermediate between metals and nonmetals

11. Section 6.2 Classifying the Elements p. 161

12. Groups of elements - family names Group IA – alkali metals  Forms “base” (or alkali) when reacting w/ H 2 O (not just dissolved!) Group 2A – alkaline earth metals  Also form bases with H 2 O; don’t dissolve well, hence “earth metals” Group 7A – halogens  Greek hals (salt) & genesis (to be born)

13. Electron Configurations in Groups sorted based on e- configs: 1) Noble gases 2) Representative elements 3) Transition metals 4) Inner transition metals Let’s now take a closer look at these.

14. Electron Configurations in Groups 1) Noble gases 1) Noble gases in Group 8A (also called Group 18)  very stable = don’t react  e- configuration full full outer s & p sublevels

15. Electron Configurations in Groups 2) Representative Elements 2) Representative Elements Groups 1A - 7A  Properties vary “Represent” all elements NOT filled s & p sublevels of highest PEL NOT filled Group # = valence e-’s

16. Electron Configurations in Groups 3) Transition metals 3) Transition metals in “B” columns s sublevel full  outer s sublevel full  Start filling “d” sublevel  “Transition” btwn metals & nonmetals

17. Electron Configurations in Groups 4) Inner Transition Metals 4) Inner Transition Metals below PT, 2 horizontal rows  outer s sublevel full  Start filling “f” sublevel

18. 1A 2A3A4A5A6A 7A 8A Elements 1A-7A groups called representative elements outer s or p filling

19. The group B called transition elements u These are called the inner transition elements, and they belong here

20. Group 1A called alkali metals (but NOT H) Group 2A called alkaline earth metals H

21. Group 8A are noble gases Group 7A called halogens

22. Periodic table rap Let’s take a quick break……

23. 1s11s1 1s 2 2s 1 1s 2 2s 2 2p 6 3s 1 1s 2 2s 2 2p 6 3s 2 3p 6 4s 1 1s 2 2s 2 2p 6 3s 2 3p 6 4s 2 3d 10 4p 6 5s 1 1s 2 2s 2 2p 6 3s 2 3p 6 4s 2 3d 10 4p 6 5s 2 4d 10 5p 6 6s 1 1s 2 2s 2 2p 6 3s 2 3p 6 4s 2 3d 10 4p 6 5s 2 4d 10 5p 6 6 s 2 4f 14 5d 10 6p 6 7s 1 H 1 Li 3 Na 11 K 19 Rb 37 Cs 55 Fr 87 Do you notice any similarity in these configurations of the alkali metals?

24. He 2 Ne 10 Ar 18 Kr 36 Xe 54 Rn 86 1s21s2 1s 2 2s 2 2p 6 1s 2 2s 2 2p 6 3s 2 3p 6 1s 2 2s 2 2p 6 3s 2 3p 6 4s 2 3d 10 4p 6 1s 2 2s 2 2p 6 3s 2 3p 6 4s 2 3d 10 4p 6 5s 2 4d 10 5p 6 1s 2 2s 2 2p 6 3s 2 3p 6 4s 2 3d 10 4p 6 5s 2 4d 10 5p 6 6s 2 4f 14 5d 10 6p 6 Do you notice any similarity in the configurations of the noble gases?

25. Elements in the s - blocks Alkali metals end in s 1 Alkaline earth metals end in s 2  should include He, but… properties of noble gases  full outer EL  group 8A s2s2 s1s1 He

26. Transition Metals - d block d1d1 d2d2 d3d3 s1d5s1d5 d5d5 d6d6 d7d7 d8d8 s 1 d 10 d 10 Note the change in configuration.

27. The P-block p1p1 p2p2 p3p3 p4p4 p5p5 p6p6

28. F - block Called “inner transition elements”

29. Each period # = energy level for s & p orbitals. 12345671234567 Period Number

30. “d” orbitals fill up in levels 1 less than period #  first “d” is 3d found in period 4. 12345671234567 3d 4d 5d

31. f orbitals start filling at 4f….2 less than period # 12345671234567 4f5f

32. Demo p. 165

33. Trends in Atomic Size Atomic Radius - half distance btwn 2 nuclei of identical atoms  Increases top-bottom  Decreases L-R  picometers 10 -12 m… 1 trillionth Radius Section 6.3 Periodic Trends p. 170

34. ALL ALL PT Trends Influenced by 3 factors: Energy Level 1. Energy Level  Higher energy levels further from nucleus Charge on nucleus 2. Charge on nucleus (# protons)  More + charge pulls e -’ s in closer Shielding effect 3. Shielding effect

35. #1. Atomic Size - Group trends Going down a group, atoms gain another PEL (floor)  atoms get….. H Li Na K Rb b i g g e r

36. #1. Atomic Size - Period Trends L to R across period:  More p+ in nucleus  More e-’s occupy same energy level stronger nuclear charge Pulls e- cloud closer to nucleus  atoms get…. Na Mg Al Si P S Cl Ar Here is an animation to explain the trend. S m a l l e r

37. Trends of Atomic Radius increases decreases increases

38. p. 172 Ions p. 172 Some compounds composed of “ions”  Ion - atom (or group of atoms) w/ + or - charge formed when e- transferred btwn atoms  Cation (loses e-’s…+ ion)  Anion (gains e-’s… - ion)

39. Cation Formation 11p+ Na atom 1 valence e- Valence e- lost in ion formation Effective nuclear charge on remaining e-’s increases. Remaining e- pulled closer to nucleus. Ionic size decreases. Result: a smaller sodium ion, Na +

40. Anion Formation 17p+ Chlorine atom with 7 valence e- One e- is added to the outer shell (from Na for example). Effective nuclear charge is reduced and the e- cloud expands. ion A chloride ion is produced. It is larger than the original atom.

41. p.173 #2. Trends in Ionization Energy p.173 Ionization energy - energy required to completely remove e- (from gaseous atom) energy required to remove only 1st e- called first ionization energy.

42. Ionization Energy second IE is E required to remove 2nd e-  Always greater than first IE third IE greater than 1st or 2nd IE IE helps predict what ions elements form Li 1+ Mg 2+ Al 3+

43. SymbolFirstSecond Third H He Li Be B C N O F Ne 1312 2731 520 900 800 1086 1402 1314 1681 2080 5247 7297 1757 2430 2352 2857 3391 3375 3963 11810 14840 3569 4619 4577 5301 6045 6276 Why did these values increase so much ? Table 6.1, p. 173

45. Cation Formation 11p+

46. Anion Formation 17p+

47. What factors determine IE? greater nuclear charge = greater IE Greater distance from nucleus decreases IE Filled & half-filled orbitals have lower energy  Easier to achieve (lower IE) Shielding effect

48. Shielding Effect e-’s in outer PEL “look thru” other PEL’s to “see” nucleus Stays same thru blocks Greater influence on IE than nuclear charge

49. Shielding Trends remains constant increases

50. Ionization Energy - Group trends p. 174 going down group  first IE decreases b/c... e- further from p+ attraction  more “shielding”

51. Ionization Energy - Period trends p. 174 Same period atoms have same: # energy levels “shielding” (within a block – slight decrease btwn “s” and “p”)  Increasing nuclear charge  IE generally increases left - right Exceptions…full & 1/2 full orbitals

52. First Ionization energy Atomic number He He greater IE than H. Both w/ same shielding (e- in 1st level)  He - greater nuclear charge H

53. First Ionization energy Atomic number H He Li lower IE than H more shielding further away l These outweigh greater nuclear charge Li

54. First Ionization energy Atomic number H He Be higher IE than Li = shielding (period) l greater nuclear charge Li Be

55. First Ionization energy Atomic number H He B has lower IE than Be l greater nuclear charge l shielding has greater influence on IE l Slight decrease (“p” e-) l “p” e- removed l “s” orbital ½ filled Li Be B

56. First Ionization energy Atomic number H He Li Be B C

57. First Ionization energy Atomic number H He Li Be B C N

58. First Ionization energy Atomic number H He Li Be B C N O Oxygen breaks the pattern, b/c removing e- leaves it w/ 1/2 filled p orbital

59. First Ionization energy Atomic number H He Li Be B C N O F

60. First Ionization energy Atomic number H He Li Be B C N O F Ne Ne has a lower IE than He  Both full but… Ne more shielding  b/c greater distance

61. First Ionization energy Atomic number H He Li Be B C N O F Ne Na has a lower IE than Li Both are s 1 Na - more shielding l Greater distance Na

63. Trends in Ionization Energy (IE) increases decreases

64. Trends in Ionic Size: Cations Cations lose e-’s  metals Cations smaller than atom they came from  lose e-’s  lose entire energy level. Cations of representative elements have noble gas config before them

65. Trends in Ionic size: Anions Anions gain e-‘s  nonmetals Anions bigger than atom they came from  same energy level  greater area nuclear charge needs to cover

66. Configuration of Ions Ions always have noble gas configurations (full outer level) Na atom is: 1s 2 2s 2 2p 6 3s 1  Forms 1+ Na ion: 1s 2 2s 2 2p 6  Same as Ne

67. Configuration of Ions Non-metals form ions by gaining e-’s to achieve noble gas configuration  configuration of noble gas after them

68. Ion Group trends Each step down a group adds energy level Ions - bigger going down  more energy levels Li 1+ Na 1+ K 1+ Rb 1+ Cs 1+

69. Ion Period Trends Across period  nuclear charge increases  Ions get smaller energy level changes btwn anions & cations Li 1+ Be 2+ B 3+ C 4+ N 3- O 2- F 1-

70. #3. Trends in Electronegativity Electronegativity (EN)- tendency for atom to attract e-’s when atom in cmpd Sharing e-, but how equally? Element w/ big EN pulls e- towards itself strongly!

71. Electronegativity Group Trend Further down group, farther e- away from nucleus  plus more e-’s atom has more willing to share Low EN

72. Electronegativity Period Trend Metals let e-’s go easily  low EN Nonmetals want more e-’s  take e-’s from others  High EN

73. Trends in Electronegativity 0 decreases increases decreases

74. Chemistry Song "Elemental Funkiness" - Mark Rosengarten The Elements – Tom Lehrer