Quantum Chemistry

1. Quantum Chemistry Electron Configurations & The Periodic Table Dr. Ron Rusay

2. Quantum Chemistry Chem 120 Track Chem 108 Electron Configurations & The Periodic Table Dr. Ron Rusay

3. Quantum Theory • Based on experimental observations of light and particles • Developed through rigorous mathematical computations • Bridges physics and chemistry • Generally described as quantum mechanics aka quantum chemistry

4. Electromagnetic Radiation(“Light”) • Energy that exhibits wave-like behavior that travels through space at 186,000 mi/s; 3 x 108 m/s • Described by the Electromagnetic Spectrum.

6. Demonstrating Light’sWave Nature

7. Frequency & Wave length

9. Waveshttp://chemistry.beloit.edu/BlueLight/waves/index.html • Waves have 4 primary characteristics: • 1. Wavelength: distance between two peaks in a wave. • 2. Frequency: number of waves per second that pass a given point in space. • 3. Amplitude: the height of the wave. • 4. Speed: speed of light is 2.9979  108 m/s.

10. Waveshttp://chemistry.beloit.edu/BlueLight/waves/index.html • Focus on 2 of the primary characteristics: • 1. Wavelength: distance between two peaks in a wave. • 2. Frequency: number of waves per second that pass a given point in space. • 3. Amplitude: the height of the wave. • 4. Speed: speed of light is 2.9979  108 m/s.

11. Wavelength and frequency  = c /  •  = frequency (s1) •  = wavelength (m) • c = speed of light (m s1)

12. QUESTION

13. 1 B) 4.12 10 s The smaller the frequency of light, the longer the wavelength. ANSWER 5 – ´

14. Planck’s Constant Transfer of energy is quantized, and can only occur in discrete units, called quanta. • E = change in energy, in J • h = Planck’s constant, 6.626  1034 J s •  = frequency, in s1 •  = wavelength, in m • c = speed of light

15. Planck’s Equation (Interactive) http://chemconnections.org/general/chem120/Flash/plancks_equation_s.html

16. Electromagnetic Energy • EM Spectrum : Chem Connections http://chemistry.beloit.edu/Stars/EMSpectrum/index.html

17. Energy and Mass • Energy has mass • E = mc2 • E = energy • m = mass • c = speed of light

18. Energy and Mass”Duality” (Hence the dual nature of light.)

19. Wavelength and Mass de Broglie’s Equation •  = wavelength, in m • h = Planck’s constant, 6.626  1034J .s = kg m2 s1 • m = mass, in kg •  = frequency, in s1

20. Atomic Spectrum of Hydrogen http://chemistry.beloit.edu/BlueLight/pages/color.html • Continuous spectrum: Contains all the wavelengths of light. • Absorbtion vs.Emission • http://chemistry.beloit.edu/BlueLight/pages/elements.html • Line (discrete) spectrum: Contains only some of the wavelengths of light.

22. http://chemconnections.org/general/chem120/Flash/atomic_absorption_s.htmlhttp://chemconnections.org/general/chem120/Flash/atomic_absorption_s.html

23. Emissions: Flame Tests

25. Electromagnetic Energy • Visible Light / Color : ChemConnections • http://chemistry.beloit.edu/Stars/applets/emission/index.html • The Perception of Colors • http://chemconnections.org/organicchem227/227assign-06.html#vision

26. Atomic Emission Spectrum of H2

28. E = Efinal state Einitial state

29. Quantum Chemistry Chem 108 Electron Configurations & The Periodic Table Dr. Ron Rusay

30. Quantum Theory • Based on experimental observations of light and particles • Developed through rigorous mathematical computations • Bridges physics and chemistry • Generally described as quantum mechanics aka quantum chemistry

31. Electromagnetic Radiation(“Light”) • Energy that exhibits wave-like behavior that travels through space at 186,000 mi/s; 3 x 108 m/s • Described by the Electromagnetic Spectrum.

33. Demonstrating Light’sWave Nature

34. http://chemconnections.org/general/chem120/Flash/atomic_absorption_s.htmlhttp://chemconnections.org/general/chem120/Flash/atomic_absorption_s.html

36. E = Efinal state Einitial state

38. https://www.youtube.com/watch?v=4QlcKuxDGrs Heisenberg Uncertainty Principle Quantum Entanglement/SuperpositionSchrödinger’s Cat: Alive or Dead?Can something be in two places at the same time? • The more accurately we know a particle’s position, the less accurately we can know its momentum or vice versa. (non-intuitive) In quantum microstates, YES.Science, 272, 1132 (1996)

39. Electron Configurations 113: Nihonium, 115: Moscovium , 117: Tennessine and 118: Oganesson

40. Quantum Numbers (QN) for Electrons(Solutions for the Schrödinger Equation:  =) Where:  = Wave function • 1. Principal QN ( integer n = 1, 2, 3, . . .) : relates to size and energy of the orbital. • 2. Angular Momentum QN ( integer lor)= 0 to n  1) : relates to shape of the orbital. • 3. Magnetic QN (integer m l orm= + l to  l) : relates to orientation of the orbital in space relative to other orbitals. • 4. Electron Spin QN : (ms = +1/2, 1/2) : relates to the spin state of the electron.

41. “ORBITAL”: Electron Probability = ||2 ||2 =  (double integral of wave function  )

42. Atomic Orbitals (3D Shapes) http://chemconnections.org/general/chem120/atomic-orbitals/orbitals.html http://www.orbitals.com/orb/orbtable.htm

43. Atomic Orbitals (3D Shapes) Electrons are described by 4 Quantum Numbers (Orbitals: First 2-3 Quantum Numbers) n = 1, 2, 3, . l = 0 to n  1) m l = + l to  l

44. QUESTION

45. B) 4 Orbitals are designated by . For = 2, has m four values. ANSWER n m l l

46. QUESTION

47. A) 0 For = 3, can be 0, 1, or 2. An orbital has an n = 3 and must be n = 4. ANSWER f- orbitals only occur when n = 4 or higher 4 -3, -2, -1, 0, +1, +2, +3 l f l

48. QUESTION

49. D) 7 orbitals have = 3 and ml = -3, -2, -1, 0, +1, +2, +3 (7 possible values). ANSWER 4 f- orbitals l = 3 3 -3, -2, -1, 0, +1, +2, +3 f l

50. Quantum Numbers : l, mlOrbital Shape & Orientation l = 0, ml = 0; (s) l = 1, ml = -1, 0,+1; (p) l = 2, ml = -2,-1, 0,+1,+2; (d)