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Periodic Patterns

1 st column of s-block. 1st Period. s-block. Periodic Patterns. Example - Hydrogen. 1s 1. Courtesy Christy Johannesson www.nisd.net/communicationsarts/pages/chem. p. s. d (n-1). f (n-2). Periodic Patterns. Shorthand Configuration Core electrons:

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Periodic Patterns

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  1. 1st column of s-block 1st Period s-block Periodic Patterns • Example - Hydrogen 1s1 Courtesy Christy Johannesson www.nisd.net/communicationsarts/pages/chem

  2. p s d (n-1) f (n-2) Periodic Patterns • Shorthand Configuration • Core electrons: • Go up one row and over to the Noble Gas. • Valence electrons: • On the next row, fill in the # of e- in each sublevel. Courtesy Christy Johannesson www.nisd.net/communicationsarts/pages/chem

  3. 32 Ge 72.61 Periodic Patterns • Example -Germanium [Ar] 4s2 3d10 4p2 Courtesy Christy Johannesson www.nisd.net/communicationsarts/pages/chem

  4. Stability • Electron Configuration Exceptions • Copper • EXPECT: [Ar] 4s2 3d9 • ACTUALLY: [Ar] 4s1 3d10 • Copper gains stability with a full d-sublevel. Courtesy Christy Johannesson www.nisd.net/communicationsarts/pages/chem

  5. Stability • Electron Configuration Exceptions • Chromium • EXPECT: [Ar] 4s2 3d4 • ACTUALLY: [Ar] 4s1 3d5 • Chromium gains stability with a half-full d-sublevel. Courtesy Christy Johannesson www.nisd.net/communicationsarts/pages/chem

  6. Cr 3d4 Cu 3d9 Electron Filling in Periodic TableExceptions s s p 1 2 d 3 K 4s1 Ca 4s2 Sc 3d1 Ti 3d2 V 3d3 Cr 3d5 Mn 3d5 Fe 3d6 Co 3d7 Ni 3d8 Cu 3d10 Zn 3d10 Ga 4p1 Ge 4p2 As 4p3 Se 4p4 Br 4p5 Kr 4p6 4 Cr 4s13d5 Cu 4s13d10 4f 4d n = 4 4p 3d Cr 4s13d5 4s n = 3 3p Energy 3s 4s 3d 2p n = 2 2s Cu 4s13d10 n = 1 1s 4s 3d

  7. Stability • Ion Electron Configuration • Write the e- config for the closest Noble Gas • EX: Oxygen ion  O2-  Ne • O2- 10e- [He] 2s2 2p6 Courtesy Christy Johannesson www.nisd.net/communicationsarts/pages/chem

  8. Development of Periodic Table J.A.R. Newlands (1864) Law of Octaves Arranged the 62 known elements into groups of seven according to increasing atomic mass. He proposed that an eighth element would then repeat the properties of the first element in the previous group. D. Mendeleev (1871) Original Periodic Table Observed properties and organized elements by atomic mass. Henry Mosley (1914) Revised Periodic Table Reorganized table by atomic number, based on observations with atomic spectra

  9. Stability • Ion Formation • Atoms gain or lose electrons to become more stable. • Isoelectronic with the Noble Gases. 3+ 1+ NA 2+ 1- 0 3- 2- Courtesy Christy Johannesson www.nisd.net/communicationsarts/pages/chem

  10. 1s 2p 2s 3p 3s 4p 3d 4s 5p 5s 4d 6p 6s 5d 7p 7s 6d 4f 5f Periodic Patterns s p 1 2 3 4 5 6 7 1s d (n-1) 6 7 f (n-2)

  11. Stability • Full energy level • Full sublevel (s, p, d, f) • Half-full sublevel Courtesy Christy Johannesson www.nisd.net/communicationsarts/pages/chem

  12. Dmitri Mendeleev (1871) • Russian • Invented “Periodic Table” • Organized all known elements by properties and by atomic mass • Predicted existence of several unknown elements Dmitri Mendeleev

  13. Five Periodic Trends Atomic Radius: distance outermost electrons from nucleus Ionization Energy: energy required to remove an electron from atom in gaseous state Metallic Character: metals lose e- to form cations; non-metals gain e- to form anions Electron Affinity: change in energy by adding anelectron to a gaseous atom Reactivity: ability of an element to react

  14. Atomic Radii of Representative Elements (nm) 1A 2A 3A 4A 5A 6A 7A Li Be C N O B F 0.088 0.077 0.070 0.066 0.064 0.152 0.111 Na Mg Al Si P S Cl 0.186 0.160 0.143 0.117 0.110 0.104 0.099 K Ca Ge As Se Br Ga 0.231 0.197 0.122 0.122 0.121 0.117 0.114 Rb Sr In Sn Sb Te I 0.162 0.140 0.141 0.137 0.133 0.244 0.215 Cs Ba At Pb Tl Po Bi 0.262 0.217 0.171 0.175 0.146 0.140 0.140 LeMay Jr, Beall, Robblee, Brower, Chemistry Connections to Our Changing World , 1996, page 175

  15. Group 13 e e e e e e e e e Li Li+ F- F 64 152 60 136 Na Na+ Al Cl- Cl 50 95 143 99 186 181 K K+ Br- Br 114 133 195 227 Trends in Atomic and Ionic Size Metals Nonmetals Group 1 Group 17 Al3+ Cations are smaller than parent atoms Anions are larger than parent atoms

  16. Key Factors Driving Trends Coulomb’s Law!!! Effective Nuclear Charge: the charge felt by electrons from the nucleus Shielding: the effect of inner “core” electrons to shield valence electrons from nuclear charge

  17. Nuclear Shielding Valence Inner electrons block the attractive force of the nucleus from the valence electrons + - - nucleus - Electrons - Electron Shield “inner” electrons

  18. First Ionization Energies(kJ/mol) s p H 1312.1 He 2372.5 Li 520.3 Be 899.5 B 800.7 C 1086.5 N 1402.4 O 1314.0 F 1681.1 Ne 2080.8 Na 495.9 Mg 737.8 Al 577.6 Si 786.5 P 1011.8 S 999.7 Cl 1251.2 Ar 1520.6 K 418.9 Ca 589.9 Ga 578.6 Ge 761.2 As 946.5 Se 940.7 Br 1142.7 Kr 1350.8 Rb 402.9 Sr 549.2 In 558.2 Sn 708.4 Sb 833.8 Te 869.0 I 1008.7 Xe 1170.3 Smoot, Price, Smith, Chemistry A Modern Course1987, page 188

  19. Shaded area on table denotes core electrons. Ionization Energies (kJ/mol) 3rd 6910 7730 2740 3220 2905 3375 3850 3945 4th 9540 10,600 11,600 4350 4950 4565 5160 5770 Element Na Mg Al Si P S Cl Ar 1st 498 736 577 787 1063 1000 1255 1519 2nd 4560 1445 1815 1575 1890 2260 2295 2665 5th 13,400 13,600 15,000 16,100 6270 6950 6560 7320 6th 16,600 18,000 18,310 19,800 21,200 8490 9360 8780 Herron, Frank, Sarquis, Sarquis, Cchrader, Kulka, Chemistry 1996, Heath, page

  20. Factors Affecting Ionization Energy Coulomb’s Law!! Effective Nuclear Charge The larger the nuclear charge, the greater the ionization energy. Shielding effect The greater the shielding effect, the less the ionization energy. Radius The greater the distance between the nucleus and the outer electrons of an atom, the less the ionization energy. Sublevel and Electron-Electron Replusion An electron from a full or half-full sublevel requires additional energy to be removed. Replusion of electrons in orbitals results in lower ionization energy. Smoot, Price, Smith, Chemistry A Modern Course 1987, page 189

  21. He Ne F N H O C Be 3s B 2p Li 2s Na 1s n • Na has a lower IE than Li • Both are s1 • Na has more shielding • Greater distance First Ionization energy Atomic number

  22. Electronegativity/Electron Affility Electronegativity: The ability of an atom in a molecule to attract shared electrons to itself. Electron Affinity: Change in energy when adding an electron Linus Pauling 1901 - 1994

  23. Electron Affinity

  24. Metals, Nonmetals, & Metalloids 1 Nonmetals 2 3 4 Metals 5 6 7 Metalloids Zumdahl, Zumdahl, DeCoste, World of Chemistry 2002, page 349

  25. Metallic Characteristics metallic character increases nonmetallic character increases metallic character increases nonmetallic character increases

  26. H 2.1 Li 1.0 Be 1.5 B 2.0 C 2.5 N 3.0 O 3.5 F 4.0 Na 0.9 Mg 1.2 Al 1.5 Si 1.8 P 2.1 S 2.5 Cl 3.0 K 0.8 Ca 1.0 Sc 1.3 Ti 1.5 V 1.6 Cr 1.6 Mn 1.5 Fe 1.8 Co 1.8 Ni 1.8 Cu 1.9 Zn 1.7 Ga 1.6 Ge 1.8 As 2.0 Se 2.4 Br 2.8 Rb 0.8 Sr 1.0 Y 1.2 Zr 1.4 Nb 1.6 Mo 1.8 Tc 1.9 Ru 2.2 Rh 2.2 Pd 2.2 Ag 1.9 Cd 1.7 In 1.7 Sn 1.8 Sb 1.9 Te 2.1 I 2.5 * Cs 0.7 Ba 0.9 La 1.1 Hf 1.3 Ta 1.5 W 1.7 Re 1.9 Os 2.2 Ir 2.2 Pt 2.2 Au 2.4 Hg 1.9 Tl 1.8 Pb 1.8 Bi 1.9 Po 2.0 At 2.2 y Fr 0.7 Ra 0.9 Ac 1.1 * Lanthanides: 1.1 - 1.3 y Actinides: 1.3 - 1.5 Below 1.0 2.0 - 2.4 1.0 - 1.4 2.5 - 2.9 1.5 - 1.9 3.0 - 4.0 Electronegativity 1A 8A 1 1 3A 5A 7A 2A 4A 6A 2 2 3 3 2B 4B 6B 8B 1B 3B 5B 7B Period 4 4 5 5 6 6 7 Hill, Petrucci, General Chemistry An Integrated Approach 2nd Edition, page 373

  27. Reactivity GROUP 1 (ALKALI METALS) and 2 (ALKALINE-EARTH) Both groups very reactive; most stable by losing 1-2 electrons. Group 1 often stored in oil (most reactive group) GROUP 17 HALOGENS Most reactive of non-metals; most stable by gaining one electron GROUP 18 NOBLE GASES Low chemical reactivity; very stable; octet valence electrons

  28. Summary of Key Periodic Trends Shielding is constant Atomic radius decreases Ionization energy increases Electronegativity/Affinity increases Nuclear charge increases Metal Reactivity decreases Non-Metal Reactivity increases Nuclear charge increases Shielding increases Atomic radius increases Ionic size increases Ionization energy decreases Electronegativity/Affinity decreases Metal Reactivity increases/non-Metal decreases 1A 0 5A 2A 3A 4A 6A 7A Ionic size (cations) Ionic size (anions) decreases decreases

  29. Ionization Energies 18 Group 1 H 1312 He 2372 Symbol First Ionization Energy (kJ/mol) Mg 738 1 1 13 15 17 2 14 16 Li 520 Be 900 B 801 C 1086 N 1402 O 1314 F 1681 Ne 2081 2 2 Na 496 Mg 738 Al 578 Si 787 P 1012 S 1000 Cl 1251 Ar 1521 3 3 12 4 6 8 9 10 11 3 5 7 Period K 419 Ca 590 Sc 633 Ti 659 V 651 Cr 653 Mn 717 Fe 762 Co 760 Ni 737 Cu 746 Zn 906 Ga 579 Ge 762 As 947 Se 941 Br 1140 Kr 1351 4 4 Rb 403 Sr 550 Y 600 Zr 640 Nb 652 Mo 684 Tc 702 Ru 710 Rh 720 Pd 804 Ag 731 Cd 868 In 558 Sn 709 Sb 834 Te 869 I 1008 Xe 1170 5 5 * Cs 376 Ba 503 La 538 Hf 659 Ta 761 W 770 Re 760 Os 839 Ir 878 Pt 868 Au 890 Hg 1007 Tl 589 Pb 716 Bi 703 Po 812 At -- Rn 1038 6 6 y Uuu -- Uub -- Uut -- Uuq -- Uup -- Uuo -- Fr -- Ra 509 Ac 490 Rf -- Db -- Sg -- Bh -- Hs -- Mt -- Ds -- 7 * Ce 534 Pr 527 Nd 533 Pm 536 Sm 545 Eu 547 Gd 592 Tb 566 Dy 573 Ho 581 Er 589 Tm 597 Yb 603 Lu 523 Lanthanide series y Th 587 Pa 570 U 598 Np 600 Pu 585 Am 578 Cm 581 Bk 601 Cf 608 Es 619 Fm 627 Md 635 No 642 Lr -- Actinide series

  30. Shaded area on table denotes core electrons. Ionization Energies (kJ/mol) 3rd 6910 7730 2740 3220 2905 3375 3850 3945 4th 9540 10,600 11,600 4350 4950 4565 5160 5770 Element Na Mg Al Si P S Cl Ar 1st 498 736 577 787 1063 1000 1255 1519 2nd 4560 1445 1815 1575 1890 2260 2295 2665 5th 13,400 13,600 15,000 16,100 6270 6950 6560 7320 6th 16,600 18,000 18,310 19,800 21,200 8490 9360 8780 Herron, Frank, Sarquis, Sarquis, Cchrader, Kulka, Chemistry 1996, Heath, page

  31. 1e- 2e- 1+ 2+ H He He n • Helium (He) has… • a greater IE than H • same shielding • greater nuclear charge H First Ionization energy Atomic number

  32. He • Li has… • lower IE than H • more shielding • Further away outweighs greater nuclear charge n H First Ionization energy Li Atomic number

  33. 2p 2s 1s He Ne n F N • Ne has a lower IE than He • Both are full energy levels, • Ne has more shielding • Greater distance H O C First Ionization energy Be B Li Atomic number

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