2. Chapter 4.1 The Development of a New Atomic Model

3. Properties of Light RLight as a wave: RVisible light is a type of electromagnetic radiation, along with X-rays, ultraviolet and infrared light, microwaves, and radio waves. RThese form the electromagnetic spectrum. RWaves have a repetitive nature and can be measured by wavelength() & frequency(). RWavelength unit is cm or nm. RFrequency unit is waves/sec or hertz (Hz). RLight as a wave: RVisible light is a type of electromagnetic radiation, along with X-rays, ultraviolet and infrared light, microwaves, and radio waves. RThese form the electromagnetic spectrum. RWaves have a repetitive nature and can be measured by wavelength() & frequency(). RWavelength unit is cm or nm. RFrequency unit is waves/sec or hertz (Hz).

4. RFrequency and wavelength are related to each other through the following equation: c = c = speed of light or 3.00 x 10 8 m/s As wavelength increases, frequency decreases and vice versa. RFrequency and wavelength are related to each other through the following equation: c = c = speed of light or 3.00 x 10 8 m/s As wavelength increases, frequency decreases and vice versa.

5. Example RDetermine the frequency () of light whose wavelength () is 6.87 x 10 -8 cm. c = c = 3.00 x 10 8 m/s = c/ Change cm to m and plug into equation = 3.00 x 10 8 m/s 6.87 x 10 -10 m =.437 x 10 18 ≈ 4.37 x 10 17 Hz RDetermine the frequency () of light whose wavelength () is 6.87 x 10 -8 cm. c = c = 3.00 x 10 8 m/s = c/ Change cm to m and plug into equation = 3.00 x 10 8 m/s 6.87 x 10 -10 m =.437 x 10 18 ≈ 4.37 x 10 17 Hz

6. RLight as a particle: RPhotoelectric effect is the emission of electrons from metal when light shines on it. RA quantum of energy is the minimum amount of energy that can be lost or gained by an atom. RA photon is a particle of electromagnetic radiation with no mass and carrying a quantum of energy. RLight as a particle: RPhotoelectric effect is the emission of electrons from metal when light shines on it. RA quantum of energy is the minimum amount of energy that can be lost or gained by an atom. RA photon is a particle of electromagnetic radiation with no mass and carrying a quantum of energy.

7. The Hydrogen-Atom Line- Emission Spectrum RWhen current is passed through a gas, it goes from the ground state to the excited state. RIt emits light known as the emission- line spectrum. RWhen an excited hydrogen atom falls to its ground state, it emits a photon of radiation. RWhen current is passed through a gas, it goes from the ground state to the excited state. RIt emits light known as the emission- line spectrum. RWhen an excited hydrogen atom falls to its ground state, it emits a photon of radiation.

8. Ch 4.2 Notes The Quantum Model of the Atom

9. Electrons as Waves RBehavior of electrons is similar to the behavior of waves. RElectron waves can only exist at certain frequencies. RBehavior of electrons is similar to the behavior of waves. RElectron waves can only exist at certain frequencies.

10. Heisenberg Uncertainty Principle RWerner Heisenberg had an idea on how to detect the location of electrons. RHeisenberg Uncertainty Principle: it is impossible to determine simultaneously both the position and velocity (speed) of an electron. RWerner Heisenberg had an idea on how to detect the location of electrons. RHeisenberg Uncertainty Principle: it is impossible to determine simultaneously both the position and velocity (speed) of an electron.

11. The Schrödinger Wave Equation RDeveloped an equation that treated electrons in atoms as waves and quantization of electron energies was an outcome of the equation. RQuantum Theory: mathematically describes the wave properties of electrons and other very small particles. RDeveloped an equation that treated electrons in atoms as waves and quantization of electron energies was an outcome of the equation. RQuantum Theory: mathematically describes the wave properties of electrons and other very small particles.

12. Principal Quantum Number n Principal Quantum Number ( n ) RMain energy level (shell) RSize of the orbital RPERIOD # RNumber of orbitals per main energy level is equal to n 2. RNumber of electrons = 2n 2. RMain energy level (shell) RSize of the orbital RPERIOD # RNumber of orbitals per main energy level is equal to n 2. RNumber of electrons = 2n 2. Courtesy Christy Johannesson www.nisd.net/communicationsarts/pages/chem 1s1s 2s2s 3s3s

13. Angular Momentum Quantum Number RIndicates the shape of the orbital, represented by l. RValues of l allowed are 0 and all positive integers less than or equal to n -1. REx. If n=2, shapes are l = 0 and l = 1 RA sublevel consists of orbitals in a main energy level with the same value of l. RIndicates the shape of the orbital, represented by l. RValues of l allowed are 0 and all positive integers less than or equal to n -1. REx. If n=2, shapes are l = 0 and l = 1 RA sublevel consists of orbitals in a main energy level with the same value of l.

14. Magnetic Quantum Number RIndicates the orientation of an orbital around the nucleus, represented by m. RValues of m are whole numbers, including zero, from –l to +l RIndicates the orientation of an orbital around the nucleus, represented by m. RValues of m are whole numbers, including zero, from –l to +l

15. Shapes of s, p, and d- Orbitals s orbital p orbitals d orbitals

16. Maximum Number of Electrons In Each Sublevel Maximum Number of Electrons In Each Sublevel Maximum Number SublevelNumber of Orbitals of Electrons s 1 2 p 3 6 d 5 10 f 7 14 LeMay Jr, Beall, Robblee, Brower, Chemistry Connections to Our Changing World, 1996, page 146

17. Copyright © 2006 Pearson Benjamin Cummings. All rights reserved.

18. Electron capacities

25. Copyright © 2006 Pearson Benjamin Cummings. All rights reserved.

26. Spin Quantum Number RA single orbital has a maximum of two electrons, and those electrons must have opposite spins. RIt has two values +1/2 and -1/2 RA single orbital has a maximum of two electrons, and those electrons must have opposite spins. RIt has two values +1/2 and -1/2

27. Ch 4.3 Electron Configurations RElectron Configurations: the arrangement of electrons in an atom. REach element has a unique electron configuration. RGround-state Electron Configuration is the lowest energy arrangement of the electrons for an element. RElectron Configurations: the arrangement of electrons in an atom. REach element has a unique electron configuration. RGround-state Electron Configuration is the lowest energy arrangement of the electrons for an element.

28. General Rules Aufbau Principle RElectrons fill the lowest energy orbitals first. R“Lazy Tenant Rule” Aufbau Principle RElectrons fill the lowest energy orbitals first. R“Lazy Tenant Rule”

29. RIGHT WRONG General Rules RHund’s Rule RWithin a sublevel, place one electron per orbital before pairing them. R“Empty Bus Seat Rule” RHund’s Rule RWithin a sublevel, place one electron per orbital before pairing them. R“Empty Bus Seat Rule” Courtesy Christy Johannesson www.nisd.net/communicationsarts/pages/chem

30. General Rules RPauli Exclusion Principle REach orbital can hold TWO electrons with opposite spins. RPauli Exclusion Principle REach orbital can hold TWO electrons with opposite spins. Courtesy Christy Johannesson www.nisd.net/communicationsarts/pages/chem Wolfgang Pauli

31. Electron Filling in Periodic Table 1 2 3 4 5 6 7 s d p s f

32. Rreally should include He, but He has the properties of the noble gases, and has a full outer level of electrons. s2s2 s1s1 Elements in the s - blocks He

33. The P- block p1p1 p2p2 p3p3 p4p4 p5p5 p6p6

34. Transition Metals - d block d1d1 d2d2 d3d3 s1d5s1d5 d5d5 d6d6 d7d7 d8d8 s 1 d 10 d 10 Note the change in configuration.

35. F - block RCalled the “inner transition elements”

37. s-block1st Period 1s 1 # element in block Periodic Patterns RExample - Hydrogen Courtesy Christy Johannesson www.nisd.net/communicationsarts/pages/chem

38. N 7e - ROrbital Notation Electron Configuration 1s 2 1s 2 2s 2 2s 2 2p 3 Notation 1s 2s 2p Courtesy Christy Johannesson www.nisd.net/communicationsarts/pages/chem N 14.0067 7

39. Electron Filling in Periodic Table K4s1K4s1 Ca 4s 2 Sc 3d 1 Ti 3d 2 V3d3V3d3 Mn 3d 5 Fe 3d 6 Co 3d 7 Ni 3d 8 Cr 3d 4 Cu 3d 9 Zn 3d 10 Ga 4p 1 Ge 4p 2 As 4p 3 Se 4p 4 Br 4p 5 Kr 4p 6 1 2 3 4 s d p s Cr 4s 1 3d 5 Cu 4s 1 3d 10 4s3d Cr 4s 1 3d 5 4s3d Cu 4s 1 3d 10 Cr 3d 5 Cu 3d 10

40. Order in which subshells are filled with electrons (Fig 19 pg 116) 1s2s3s4s5s6s7s1s2s3s4s5s6s7s 2p 3p 4p 5p 6p 7p 3d4d5d6d 3d4d5d6d 4f5f 4f5f 1s 2s 2p 3s 3p 4s 3d 4p 5s 4d … 2 2 6 2 6 2 10 6 2 10

41. [Ar]4s 2 3d 10 4p 2 Shorthand Electron Configuration Germanium RExample - Germanium Courtesy Christy Johannesson www.nisd.net/communicationsarts/pages/chem Ge 72.61 32

42. Core electrons: Inside Electrons Valence Electrons: electrons in the _________-_______ energy level (or shell). They will be “___” electrons and “___” electrons only. Counting Valence Electrons Group A # = number of valence electrons (only exception Helium = __ e - ’s) Examples: Ca = __ e - ’sNitrogen = __ e - ’sArgon = __ e - ’s d-block and f-block = ___valence e - ’s Core and Valence Electrons outermost sp 2 58 2 2

43. neon's electron configuration (1s 2 2s 2 2p 6 ) Shorthand Configuration [Ne] 3s 1 third energy level one electron in the s orbital orbital shape Na = [1s 2 2s 2 2p 6 ] 3s 1 electron configuration A B C D

44. Shorthand Configuration S 16e - Valence Electrons Core Electrons S16e - [Ne] 3s 2 3p 4 1s 2 2s 2 2p 6 3s 2 3p 4 Notation RLonghand Configuration Courtesy Christy Johannesson www.nisd.net/communicationsarts/pages/chem S 32.066 16