Principle Shells and Subshells • Principle electronic shell, n = 1, 2, 3… • Angular momentum quantum number, l = 0, 1, 2…(n-1) l = 0, s l = 1, p l = 2, d l = 3, f Prentice-Hall © 2002 • Magnetic quantum number, ml= - l …-2, -1, 0, 1, 2…+l • Magnetic spin number, ms= + ½ , - ½ General Chemistry: Chapter 9 Quantum Numbers and the Periodic Table l = 0, m = 0, m = +/- ½ l l = 1, ml = -1, 0, 1, ms = +/- ½ s n=1 l = 2, m = -2, -1, 0, 1, 2, m = +/- ½ n=2 n=3 n=4 l s s p d n=5 n=6 n=7 f l = 3, ml = -3, -2, -1, 0, 1, 2, 3, ms = +/- ½ Prentice-Hall © 2002 General Chemistry: Chapter 9 9-11 Electron Configurations • Aufbau process. – Build up and minimize energy. • Pauli Exclusion Principle. – No two electrons can have all four quantum numbers alike. • Hund’s Rule. – Degenerate orbitals are occupied singly first. Prentice-Hall © 2002 General Chemistry: Chapter 9 Sample Question Write the electron configuration of chlorine. Identify both the the core and valence electrons. Is this element paramagnetic or diamagnetic? 1s2 2s2 2p6 3p5 3s2 core electrons (neon core) valence electrons The unpaired electron makes chlorine paramagnetic. If all electrons were paired, it would be diamagnetic. Cl: 1s22s22p63s23p5 Prentice-Hall © 2002 or [Ne]3s23p5 General Chemistry: Chapter 9 Sample Question • Concerning the electrons in the shells, subshells and orbitals of an atom, how many can have: a) n = 3, l = 2, ml = 0, ms = + ½ Only one electron can have these 4 quantum numbers b) n = 3, l = 2, ml = 0, Two electrons can have these 3 quantum numbers c) n = 3, l = 2, Ten electrons can have these 2 quantum numbers d) n = 3 Eighteen electrons can have this quantum number e) n = 3, l = 2, ms = + ½ Five electrons can have these quantum numbers Prentice-Hall © 2002 General Chemistry: Chapter 9 Summary • Frequency, wavelength, velocity v=c/l • Quantum Theory E = h v = hc/l • Photoelectric effect • Bohr Atom (orbital energy levels) En = -RH / n2 Prentice-Hall © 2002 General Chemistry: Chapter 9 Summary • Ionization Energy En = -Z2 RH / n2 • Wave-Particle Duality l = h/p = h/mu • Quantum Numbers and Electron Orbitals n, l, ml, ms s, p, d, f shapes of orbitals • Assigning Electrons to orbitals Prentice-Hall © 2002 General Chemistry: Chapter 9 Chapter 9 Questions 1, 2, 3, 4, 12, 15, 17, 19, 22, 25, 34, 35, 41, 67, 69, 71, 83, 85, 93, 98 Prentice-Hall © 2002 General Chemistry: Chapter 9 General Chemistry Principles and Modern Applications Petrucci • Harwood • Herring 8th Edition Chapter 10: The Periodic Table and Some Atomic Properties Philip Dutton University of Windsor, Canada N9B 3P4 Prentice-Hall © 2002 (modified 2003 by Dr. Paul Root and 2005 by Dr. David Tramontozzi) Prentice-Hall © 2002 General Chemistry: Chapter 10 Contents 10-1 Classifying the Elements: The Periodic Law and the Periodic Table 10-2 Metals and Nonmetals and Their Ions 10-3 The Sizes of Atoms and Ions 10-4 Ionization Energy 10-5 Electron Affinity 10-6 Magnetic Properties 10-7 Periodic Properties of the Element Prentice-Hall © 2002 General Chemistry: Chapter 10 10-1 Classifying the Elements: The Periodic Law and the Periodic Table • 1869, Dimitri Mendeleev Lother Meyer When the elements are arranged in order of increasing atomic mass, certain sets of properties recur periodically. Prentice-Hall © 2002 General Chemistry: Chapter 10 Periodic Law Meyer’s results High atomic volumes occur periodically for the alkali metals. Other physical properties such as hardness, compressibility and bp’s are found to repeat periodically Prentice-Hall © 2002 General Chemistry: Chapter 10 Mendeleev’s Periodic Table 1871 — = 44 — = 68 — = 72 —= 100 Mendeleev’s table left holes for yet to be discovered elements. Similar elements fall in vertical groups and properties change gradually from top to bottom Prentice-Hall © 2002 General Chemistry: Chapter 10 Predicted Elements were Found Prentice-Hall © 2002 General Chemistry: Chapter 10 X-Ray Spectra • Moseley 1913 –X-ray emission is explained in terms of transitions in which edrop into orbits close to the atomic nucleus. –Correlated frequencies to nuclear charges. • = A (Z – b)2 –Used to predict new elements (43, 61, 75) later discovered. Prentice-Hall © 2002 General Chemistry: Chapter 10 Alkali Metals The Periodic table Alkaline Earths Halogens Main Group Transition Metals Main Group Prentice-Hall © 2002 Lanthanides and Actinides General Chemistry: Chapter 10 Noble Gases 10-2 Metals and Nonmetals and Their Ions • Metals – Good conductors of heat and electricity. – Malleable and ductile. – Moderate to high melting points. • Nonmetals – Nonconductors of heat and electricity. – Brittle solids. – Some are gases at room temperature. Prentice-Hall © 2002 General Chemistry: Chapter 10 Metals Tend to Lose Electrons Lose enough electrons to attain a noble gas electron configuration. Prentice-Hall © 2002 General Chemistry: Chapter 10 Nonmetals Tend to Gain Electrons Gain enough electrons to attain a noble gas electron configuration. Prentice-Hall © 2002 General Chemistry: Chapter 9 Electron Configuration of Some Ions Prentice-Hall © 2002 General Chemistry: Chapter 9 10-3 The Sizes of Atoms and Ions ½ the distance between the nuclei of two identical atoms joined by a single covalent bond ½ the distance between the nuclei of two identical metal atoms in a crystalline solid. The distance between the nuclei of ions joined by an ionic bond. Prentice-Hall © 2002 General Chemistry: Chapter 9 Atomic Radius Prentice-Hall © 2002 General Chemistry: Chapter 9 Screening and Penetration Zeff = Z – S Zeff2 En = - RH 2 n Prentice-Hall © 2002 General Chemistry: Chapter 9 Cationic Radii Prentice-Hall © 2002 General Chemistry: Chapter 9 Anionic Radii Prentice-Hall © 2002 General Chemistry: Chapter 9 Atomic and Ionic Radii Cations are smaller than atoms from which formed. For isoelectronic cations, more positive charge, smaller radius. Anions, larger than corresponding. For isoelectronic anions, more negative charge, larger radius. Prentice-Hall © 2002 General Chemistry: Chapter 9 In general, atomic radius increases going from top to bottom in a group In general, atomic radius decreases going from left to right across a period