1. Dr. S. M. Condren Chapter 7 Quantum Theory of the Atom

2. Dr. S. M. Condren Electromagnetic Radiation Electromagnetic wave A wave of energy having a frequency within the electromagnetic spectrum and propagated as a periodic disturbance of the electromagnetic field when an electric charge oscillates or accelerates.

3. Dr. S. M. Condren Electromagnetic Radiation Electromagnetic wave wavelength frequency amplitude

4. Dr. S. M. Condren Electromagnetic Radiation = c where  => frequency  => wavelength c => speed of light

5. Dr. S. M. Condren Wave Nature of the Electron

6. Dr. S. M. Condren Electromagnetic Spectrum

7. Dr. S. M. Condren Line Emission Spectrum

8. Dr. S. M. Condren Line Spectrum A spectrum produced by a luminous gas or vapor and appearing as distinct lines characteristic of the various elements constituting the gas.

9. Dr. S. M. Condren Emission Spectrum The spectrum of bright lines, bands, or continuous radiation characteristic of and determined by a specific emitting substance subjected to a specific kind of excitation.

10. Dr. S. M. Condren Ground State The state of least possible energy in a physical system, as of elementary particles. Also called ground level.

11. Dr. S. M. Condren Excited State Being at an energy level higher than the ground state.

12. Dr. S. M. Condren Photoelectric Effect the emission of electrons by substances, especially metals, when light falls on their surfaces.

13. Dr. S. M. Condren Photoelectric Effect

14. Dr. S. M. Condren Quantum Mechanics Quantum theory the theory of the structure and behavior of atoms and molecules.

15. Dr. S. M. Condren Black Body Radiation http://www.cbu.edu/~mcondren/C11599/BBvis.mov

16. Dr. S. M. Condren Electromagnetic Radiation E hi - E lo = hc/ where E => energy h => Planck's constant c => speed of light  => wavelength

17. Dr. S. M. Condren Photons The quantum of electromagnetic energy, generally regarded as a discrete particle having zero mass, no electric charge, and an indefinitely long lifetime.

18. Dr. S. M. Condren Dispersion of White Light

19. Dr. S. M. Condren The Atomic Spectrum of Hydrogen and the Bohr Model Bohr Model for the Hydrogen Atom mnr = nh/2p

20. Dr. S. M. Condren Bohr Atom

21. Dr. S. M. Condren Bohr Model E = -B/n 2 where n => quantum number 1, 2, 3, 4, 5, 6, 7, etc

22. Dr. S. M. Condren Bohr Model for hydrogen ground state: n = 1 excited state: n > 1

23. Dr. S. M. Condren Bohr Model E = (-2.179 X 10 -18 J/part.) (6.022 X 10 23 part./mole) (1 kJ/10 3 J)/n 2 = (-1312 kJ/mol)(1/n 2 )

24. Dr. S. M. Condren Electron Transition in a Hydrogen Atom Lyman series => ultraviolet n > 1 ==> n = 1 Balmer series => visible light n > 2 ==> n = 2 Paschen series => infrared n > 3 ==> n = 3

25. Dr. S. M. Condren Line Spectra See CHEMWORKS software

26. Dr. S. M. Condren Absorption Spectrum Light shinning on a sample causes electrons to be excited from the ground state to an excited state wavelengths of that energy are removed from transmitted spectra

27. Dr. S. M. Condren Knowing diamond is transparent, which curve best represents the absorption spectrum of diamond (see below)? A, B, C

28. Dr. S. M. Condren According to the energy diagram below for the Bohr model of the hydrogen atom, if an electron jumps from E1 to E2, energy is absorbed emitted not involved

29. Dr. S. M. Condren Heisenberg, Werner 1901–76, German physicist 1932 Nobel Prize in physics A founder of QUANTUM MECHANICS, he is famous for his uncertainty principle, which states that it is impossible to determine both the position and momentum of a subatomic particle (such as the electron) with arbitrarily high accuracy.

30. Dr. S. M. Condren Heissenberg Uncertainty Principle “ it is impossible to determine both the position and momentum of a subatomic particle (such as the electron) with arbitrarily high accuracy” The effect of this principle is to convert the laws of physics into statements about relative, instead of absolute, certainties.

31. Dr. S. M. Condren Orbitals region of probability of finding an electron around the nucleus 5 types => s p d f maximum of 2 electrons per orbital

32. Dr. S. M. Condren Pure Atomic Orbitals shape # of orbitals / energy level s spherical 1 p dumbbell 3 d complex 5 f very complex 7

33. Dr. S. M. Condren Atomic Orbitals, s-type

34. Dr. S. M. Condren Atomic Orbitals, p-type

35. Dr. S. M. Condren Atomic Orbitals, d-type

36. Dr. S. M. Condren Atomic Orbitals, f-type

37. Dr. S. M. Condren Shapes of Orbitals http://www.colby.edu/chemistry/OChem/DEMOS/Orbitals.html