Lecture 9: Tentative material to be covered for Exam 2

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Quantum Mechanics and the Hydrogen Atom, Many-Electron Atoms and Chemical Bonding, Molecular Orbitals, Spectroscopy, and Chemical Bonding,... as the main contents of the lesson lecture 9 "Tentative material to be covered for Exam 2". Invite you to consult the lesson for more documents serving the academic needs and research.

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Nội dung Text: Lecture 9: Tentative material to be covered for Exam 2

Tentative material to be covered for Exam 2 (Wednesday, October 27) Chapter 16 Quantum Mechanics and the Hydrogen Atom 16.1 Waves and Light 16.2 Paradoxes in Classical Physics 16.3 Planck, Einstein, and Bohr 16.4 Waves, Particles, and the Schroedinger Equation 16.5 The Hydrogen Atom Chapter 17 Many-Electron Atoms and Chemical Bonding 17.1 Many-Electron Atoms and the Periodic Table 17.2 Experimental Measures of Orbital Energies 17.3 Sizes of Atoms and Ions 17.4 Properties of the Chemical Bond 17.5 Ionic and Covalent Bonds 17.6 Oxidation States and Chemical Bonding Chapter 18 Molecular Orbitals, Spectroscopy, and Chemical Bonding 18.1 Diatomic Molecules 18.2 Polyatomic Molecules 18.3 The Conjugation of Bonds and Resonance Structures 18.4 The Interaction of Light with Molecules 18.5 Atmospheric Chemistry and Air Pollution
Chapter 16 Quantum Mechanics and the Hydrogen Atom 16.1 Waves and Light Atomic Spectra I 16.2 Paradoxes in Classical Physics Ultraviolet Catastrophe Photoelectric effect 16.3 Planck, Einstein, and Bohr Planck’s Constant, Quanta and Photons Bohr Atom Atomic Spectra II 16.4 Waves, Particles, and the Schroedinger Equation Schroedinger Equation (Wave Equation) 16.5 The Hydrogen Atom Sizes and Shapes of Orbitals Electron Spin
Review of the development of the Bohr atom A Movie from the Mechanical Universe
Schroedinger: If electrons are waves, their postion and motion in space must obey a wave equation. Solutions of wave equations yield wavefunctions, , which contain the information required to describe ALL of the properties of the wave. Provides a picture of the electronic distributions of the electrons about an the nucleus of an atom and about the connected nuclei of a molecule. Schroedinger thinking about his equation.
Particles are out, waves are in. But the mathematics of waves is very complex!
Wavefunctions and orbitals Obital: defined by the quantum numbers n, l and ml Orbital is a wavefunction Orbital is a region of space occupied by an electron Orbitals has energies, shapes and orientation in space
Quantum Numbers (QN) Shorthand notation for orbitals Principal QN: Rule: l = 0, s orbital; l = 1, n = 1, 2, 3, 4…… p orbital; l = 2, d orbital Angular momentum QN: l = 3, f orbital l = 0, 1, 2, 3…. (n 1) 1s, 2s, 2p, 3s, 3p, 4s, 4p, 4d, etc. Rule: l = (n 1) Magnetic QN: ml = …2, 1, 0, 1, 2, .. Rule: l….0….+l
Recall the gaps between the energy levels of the H atom. Big initial gap and then smaller and smaller gaps.
The energy of an orbital of a hydrogen atom or any one electron atom only depends on the value of n shell = all orbitals with the same value of n subshell = all orbitals with the same value of n and l an orbital is fully defined by three quantum numbers, n, l, and m l Each shell of QN = n contains n subshells n = 1, one subshell n= 2, two subshells, etc Each subshell of QN = l, contains 2l + 1 orbitals l = 0, 2(0) + 1 = 1 l = 1, 2(1) + 1 = 3
Sizes, Shapes, and orientations of orbitals n determines size; l determines shape ml determines orientation
Nodes in orbitals: s orbitals: 1s no nodes, 2s one node, 3s two nodes
Nodes in orbitals: 2p orbitals: angular node that passes through the nucleus Orbital is “dumb bell” shaped Important: the + and that is shown for a p orbital refers to the mathematical sign of the wavefunction, not electric charge!
Nodes in orbitals: 3d orbitals: two angular nodes that passes through the nucleus Orbital is “four leaf clover” shaped d orbitals are important for metals
The fourth quantum number: Electron Spin m s = +1/2 (spin up) or 1/2 (spin down) Spin is a fundamental property of electrons, like its charge and mass. (spin up) (spin down)
Electrons in an orbital must have different values of ms This statement demands that if there are two electrons in an orbital one must have ms = +1/2 (spin up) and the other must have ms = 1/2 (spin down) This is the Pauli Exclusion Principle An empty orbital is fully described by the three quantum numbers: n, l and ml An electron in an orbital is fully described by the four quantum numbers: n, l, ml and ms
Chapter 17 ManyElectron Atoms and Chemical Bonding 17.1 ManyElectron Atoms and the Periodic Table 17.2 Experimental Measures of Orbital Energies 17.3 Sizes of Atoms and Ions 17.4 Properties of the Chemical Bond 17.5 Ionic and Covalent Bonds 17.6 Oxidation States and Chemical Bonding
Chapter 17 The Many Electron Atom Goal: Construct the periodic table based on quantum numbers (1) Solve the wave equation exactly for the H atom (2) Use the exact orbitals for the H atom as a starting approximation for the many electron atom (3) Quantum numbers obtained for H atom used to describe the many electron atom