Copyright©2000 by Houghton Mifflin Company. All rights reserved. 1 Chemistry FIFTH EDITION by Steven S. Zumdahl University of Illinois
Copyright©2000 by Houghton Mifflin Company. All rights reserved. 2 Chemistry FIFTH EDITION Chapter 7 Atomic Structure and Periodicity
Copyright©2000 by Houghton Mifflin Company. All rights reserved. 3 Section 7.12 Periodic Trends in Atomic Properties Ionization Energy Electron Affinity Atomic size
Copyright©2000 by Houghton Mifflin Company. All rights reserved. 4 Ionization Energy The quantity of energy required to remove an electron from the gaseous atom or ion. X (g) X + (g) + e -
Copyright©2000 by Houghton Mifflin Company. All rights reserved. 5 Al (g) Al + (g) + e - I 1 = 580 kJ/mole Al + (g) Al 2+ (g) + e- I 2 = 1815 kJ/mole Al 2+ (g) Al 3+ (g) + e- I 3 = 2740 kJ/mole Al 3+ (g) Al 4+ (g) + e- I 4 = kJ/mole Consider step-ionization:
Copyright©2000 by Houghton Mifflin Company. All rights reserved. 6 2 nd IE larger than 1 st. Largest jump after removing Ve -. See Table 7.5 page 328.
Copyright©2000 by Houghton Mifflin Company. All rights reserved. 7 Figure 7.31 The Values of First Ionization Energy for the Elements in the First Six Periods
Copyright©2000 by Houghton Mifflin Company. All rights reserved. 8 Periodic Trends First ionization energy: increases from left to right across a period; decreases going down a group.
Copyright©2000 by Houghton Mifflin Company. All rights reserved. 9 Figure 7.32 Trends in Ionization Energies for the Representative Elements
Copyright©2000 by Houghton Mifflin Company. All rights reserved. 10 Let’s Read!!! Page 329 – 330.
Copyright©2000 by Houghton Mifflin Company. All rights reserved. 11 Electron Affinity The energy change associated with the addition of an electron to a gaseous atom. X(g) + e X (g) If addition of an electron is exothermic, then EA is negative.
Copyright©2000 by Houghton Mifflin Company. All rights reserved. 12 EA generally becomes more negative from L R across a period. EA becomes more positive as you go down a group. There are numerous EXCEPTIONS!
Copyright©2000 by Houghton Mifflin Company. All rights reserved. 13 Figure 7.33 The Electronic Affinity Values for Atoms Among the First 20 Elements that Form Stable, Isolated X - Ions
Copyright©2000 by Houghton Mifflin Company. All rights reserved. 14 Atomic Radius Just as size of orbital can’t be exactly specified, Size of an atom can’t be exactly specified. 1) Covalent Atomic radii 2) Metallic Radii
Copyright©2000 by Houghton Mifflin Company. All rights reserved. 15 Figure 7.34 The Radius of an Atom
Copyright©2000 by Houghton Mifflin Company. All rights reserved. 16 Figure 7.35 Atomic Radii for Selected Atoms
Copyright©2000 by Houghton Mifflin Company. All rights reserved. 17 Section 7.13 Information Contained in the Periodic Table Grps. of Representative elements exhibit similar chemical properties that change in a regular way. Each group has the same valence electron configuration.
Copyright©2000 by Houghton Mifflin Company. All rights reserved. 18 It is the number and type of valence electrons that primarily determine an atoms chemistry.
Copyright©2000 by Houghton Mifflin Company. All rights reserved. 19 Information Contained in the Periodic Table Certain groups have special names (alkali metals, halogens, etc). Metals and nonmetals are characterized by their chemical and physical properties.
Copyright©2000 by Houghton Mifflin Company. All rights reserved. 20 Figure 7.36 Special Names for Groups in the Periodic Table
Copyright©2000 by Houghton Mifflin Company. All rights reserved. 21 Metals: Tend to give up electrons Form positive ions Low ionization energy Non-metals: Tend to gain electrons Form negative ions Large ionization energy Large negative electron affinity
Copyright©2000 by Houghton Mifflin Company. All rights reserved. 22 Metalloids Properties of both metals and non-metals
Copyright©2000 by Houghton Mifflin Company. All rights reserved. 23 The Alkali Metals Read pages 335 – 338. Write a detailed summary of this section. Include properties & common reactions.