1. …and, in conclusion…

2. You will need to know the contributions of… Bohr Planck Einstein Heisenberg de Broglie

3. Q: How is light produced?

4. A: An excited electron…

5. Q: How is light produced? A: An excited electron… loses energy…

6. Q: How is light produced? A: An excited electron… loses energy… as it falls…

7. Q: How is light produced? A: An excited electron… loses energy… as it falls… from a higher to a lower energy level,…

8. Q: How is light produced? A: An excited electron… loses energy… as it falls… from a higher to a lower energy level,… emitting that energy…

9. Q: How is light produced? A: An excited electron… loses energy… as it falls… from a higher to a lower energy level,… emitting that energy… as a photon of light

10. An electron that gains energy is excited:  moves to a higher energy level,  physically moves away from nucleus An electron in its normal position is in its ground state * (gains energy) Ground state Excited *

11. Light is produced * As it loses energy Ground state Excited *

12. We use a * to mark an excited electron or atom. An atom can be excited by:

13. We use a * to mark an excited electron or atom. An atom can be excited by: Heat (light bulbs, stars, sparks, flames) Electricity (sparks, fluorescent bulbs) or Chem. rxns (lightning bugs, glow sticks)

14. Let’s do the wave.

15. The wave equation Where  c is the speed of light, 3.00 x 10 8 m/s   is the wavelength (the symbol, lambda, is the Greek “l” for length) and  is the frequency (the symbol, nu, is the Greek “n”) c=

16. Please notice: Wavelength and frequency are inversely related. When wavelength increases, frequency decreases.

17. Q: What is the frequency of light that has a wavelength of 570 nm(5.7x10 -7 m)?

18. c=

19. Q: What is the frequency of light that has a wavelength of 570 nm(5.7x10 -7 m)? c=  =c/

20. Q: What is the frequency of light that has a wavelength of 570 nm(5.7x10 -7 m)?  c=  =c/ =(3.00x10 8 m/s) / (5.7x10 -7 m)

21. Q: What is the frequency of light that has a wavelength of 570 nm(5.7x10 -7 m)? c=  =c/ =(3.00x10 8 m/s) / (5.7x10 -7 m) 5.3 x 10 14 /s =5.3 x 10 14 Hz

22. Next: Planck’s equation The energy of a photon is directly related to its frequency E=h where E is the energy (in Joules), is the frequency (in waves/s, or Hz), and h is the conversion factor, Planck’s constant. h=6.63 x 10 -34 Js

23. The electromagnetic spectrum

24. For any pair-- Which has greater,, E, v?

25. The electromagnetic spectrum Increasing wavelength Increasing frequency Increasing energy and, c is the velocity of light (c for constant!)

26. Visible light 400 nm 700 nm Short wavelength High energy High frequency Long wavelength Low energy Low frequency

27. Fill in the missing information Type of photon c= 3x10 8 m/s (m) (s -1 ) E (per photon) 450 nm 93.3 MHz 353 m 9.47 x 10 -21 J 4.03 x 10 -19 J

28. Fill in the missing information Type of photon c= 3x10 8 m/s (m) (s -1 ) E (per photon) 3.00 x 10 8 m/s 450 nm6.67 x 10 14 Hz 4.42 x 10 -19 J 93.3 MHz 353 m 9.47 x 10 -21 J 4.03 x 10 -19 J

29. Fill in the missing information Type of photon c= 3x10 8 m/s (m) (s -1 ) E (per photon) 3.00 x 10 8 m/s 450 nm6.67 x 10 14 Hz 4.42 x 10 -19 J 3.00 x 10 8 m/s 3.22 m93.3 MHz6.19 x 10 -26 J 353 m 9.47 x 10 -21 J 4.03 x 10 -19 J

30. Fill in the missing information Type of photon c= 3x10 8 m/s (m) (s -1 ) E (per photon) 3.00 x 10 8 m/s 450 nm6.67 x 10 14 Hz 4.42 x 10 -19 J 3.00 x 10 8 m/s 3.22 m93.3 MHz6.19 x 10 -26 J 3.00 x 10 8 m/s 353 m8.50 x 10 5 Hz 5.63 x 10 -28 J 9.47 x 10 -21 J 4.03 x 10 -19 J

31. Fill in the missing information Type of photon c= 3x10 8 m/s (m) (s -1 ) E (per photon) 3.00 x 10 8 m/s 450 nm6.67 x 10 14 Hz 4.42 x 10 -19 J 3.00 x 10 8 m/s 3.22 m93.3 MHz6.19 x 10 -26 J 3.00 x 10 8 m/s 353 m8.50 x 10 5 Hz 5.63 x 10 -28 J 3.00 x 10 8 m/s 2.10 x 10 -5 m 1.43 x 10 13 Hz 9.47 x 10 -21 J 4.03 x 10 -19 J

32. Fill in the missing information Type of photon c= 3x10 8 m/s (m) (s -1 ) E (per photon) 3.00 x 10 8 m/s 450 nm6.67 x 10 14 Hz 4.42 x 10 -19 J 3.00 x 10 8 m/s 3.22 m93.3 MHz6.19 x 10 -26 J 3.00 x 10 8 m/s 353 m8.50 x 10 5 Hz 5.63 x 10 -28 J 3.00 x 10 8 m/s 2.10 x 10 -5 m 1.43 x 10 13 Hz 9.47 x 10 -21 J 3.00 x 10 8 m/s 4.94 x 10 -7 m 6.08 x 10 14 Hz 4.03 x 10 -19 J

33. Fill in the missing information Type of photon c= 3x10 8 m/s (m) (s -1 ) E (per photon) Blue or indigo light 3.00 x 10 8 m/s 450 nm6.67 x 10 14 Hz 4.42 x 10 -19 J FM radio3.00 x 10 8 m/s 3.22 m93.3 MHz6.19 x 10 -26 J AM radio3.00 x 10 8 m/s 353 m8.50 x 10 5 Hz 5.63 x 10 -28 J IR3.00 x 10 8 m/s 2.10 x 10 -5 m 1.43 x 10 13 Hz 9.47 x 10 -21 J Blue or Green light 3.00 x 10 8 m/s 4.94 x 10 -7 m 6.08 x 10 14 Hz 4.03 x 10 -19 J

34. The Bohr Model of the atom Bohr’s solar system model -- shows why the H gives off only 4 wavelengths of visible light. He calculated the energy that the electrons did give off, and the differences in energy.

35. Bohr drew a picture like this Electron loses energy Electron gains energy

36. These 4. No more. There is nothing between the levels– no “half-transitions” Visible wavelengths produced by hydrogen atoms

37. In the hydrogen spectrum The wavelengths are: –410 nm (violet) –434 nm (blue) –486 nm (green) –656 nm (red)

38. 4.85x10 -19 J 4.58x10 -19 J 4.09x10 -19 J 3.03x10 -19 J In the hydrogen spectrum

39. 4.85x10 -19 J 4.58x10 -19 J 4.09x10 -19 J 3.03x10 -19 J In the hydrogen spectrum What is the energy difference between these two levels?

40. 4.85x10 -19 J 4.58x10 -19 J 4.09x10 -19 J 3.03x10 -19 J In the hydrogen spectrum What is the energy difference between these two levels?.49 x 10 -19 J

41. These energies represent the differences in the energy levels… …and that’s how we know where the energy levels are.

42. Other phenomena that teach us about electrons and light The photoelectric effect –Described by Einstein for his Nobel prize –Light knocks electrons off a metal –Indicates the particle nature of light One photon excites one electron

43. Other phenomena that teach us about electrons and light Heisenberg’s Uncertainty Principle –“You cannot determine both the location and momentum of a particle exactly.” –If you measure one, you change the other unpredictably –Leads to the wave and particle natures of everything

44. Gratuitous joke Heisenberg was pulled over on the highway. The officer asks, “Do you know how fast you were going?” Heisenberg replies,

45. Gratuitous joke Heisenberg was pulled over on the highway. The officer asks, “Do you know how fast you were going?” Heisenberg replies, “No, but I do know where I am!”

46. Other phenomena that teach us about electrons and light DeBroglie’s wavelength –Describes the wave nature of particles –Considers the uncertainty in position as a wavelength

47. Electron Configurations …and now, the rest of the story

48. Fe (2,8,14,2) --An electron configuration (EC) shows the location of all electrons in an atom or ion. --In an atom, number of electrons = number of protons = atomic number --Electrons are found around the nucleus of an atom in specific energy levels.

49. Levels have sublevels!

50. Sublevels have orbitals!

51. 1st energy level -has one sublevel, 1s -An s sublevel (spherical) has one orbital, -An orbital can hold two electrons

52. So the electron configuration of hydrogen and helium are more properly written 1 H 1s 1 2 He 1s 2

53. 1 H 1s 1 2 He 1s 2 The 1 refers to the energy level

54. 1 H 1s 1 2 He 1s 2 The s refers to the sublevel

55. 1 H 1s 1 2 He 1s 2 The superscripts are the number of electrons in this sublevel.

56. 2 nd energy level -has 2s (bigger, still spherical) and 2p (has 3 bi-lobed orbitals in x, y, and z directions) -holds up to 8 electrons total (2 in the s and 3 x 2 in the p)

57. 3 Li 1s 2 2s 1 4 Be 1s 2 2s 2 5 B 1s 2 2s 2 2p 1 6 C 1s 2 2s 2 2p 2 7 N 1s 2 2s 2 2p 3 …

58. Third energy level  has three sublevels, 3s, 3p, and 3d.  The 3s and 3p sublevels are similar in structure (but bigger) than the s and p sublevels seen before.

59. The 3d sublevel (and any d) has five orbitals of varying shapes. These orbitals can hold two electrons each for a total of ten electrons. The 3d sublevel is the highest energy sublevel of energy level 3, so high, in fact, that energy level 4 begins to fill (the 4s sublevel fills) before the 3d sublevel

60. See text

61. See handout  The fourth energy level has four sublevels (notice the trend?) They are called 4s, 4p, 4d, and 4f. The s, p, and d sublevels are structured as before.

62. See handout  The f sublevel has seven orbitals, and can hold up to fourteen electrons.  The 5s sublevel is filled before the 4d, and the 5p and 6s sublevels precede the 4f.  Let’s look at a picture instead

63. You must remember this… s=1 orbital, 2 electrons p=3 orbitals, 6 electrons d=5 orbitals, 10 electrons f=7 orbitals, 14 electrons

64. The Aufbau diagram  This structure is shown below. Boxes are orbitals, each can hold two electrons

66. Rules, rules, rules. Orbitals are filled according to three rules: –Aufbau (building up) principle—lower energy sublevels are filled first –Pauli exclusion principle—electrons sharing an orbital must have opposite spins –Hund’s Rule—when a sublevel has several orbitals, electrons will distribute to separate orbitals with parallel spins, before sharing orbitals with opposite spins

68. Levels have sublevels All Electron configurations are some subset of the order shown below. Only the last sublevel might be incomplete 1s 2 2s 2 2p 6 3s 2 3p 6 4s 2 3d 10 4p 6 5s 2 4d 10 5p 6 6s 2 4f 14 5d 10 6p 6 7s 2 5f 14 6d 10 7p 6 …

69. Watch out for two things 1s 2 2s 2 2p 6 3s 2 3p 6 4s 2 3d 10 4p 6 5s 2 4d 10 5p 6 6s 2 4f 14 5d 10 6p 6 7s 2 5f 14 6d 10 7p 6 … gets old. Ex: 87 Fr 1s 2 2s 2 2p 6 3s 2 3p 6 4s 2 3d 10 4p 6 5s 2 4d 10 5p 6 6s 2 4f 14 5d 10 6p 6 7s 1  87 Fr [Rn] 7s 1 (Radon is a noble gas, and accounts for the first 86 electrons) Look for the last octet and use a noble gas core

70. Practice: Write the full EC for Titanium (element 22) and write the EC with a noble gas core

71. Practice: Write the full EC for Titanium (element 22) and write the EC with a noble gas core A) Ti 1s 2 2s 2 2p 6 3s 2 3p 6 4s 2 3d 2 and Ti [Ar] 4s 2 3d 2

72. …and watch out for Cu and Cr! Chromium, copper and a few others rearrange electrons to become more stable. Sublevel energies go down when a sublevel is full or half full. Cr 1s 2 2s 2 2p 6 3s 2 3p 6 4s 2 3d 4 becomes Cr 1s 2 2s 2 2p 6 3s 2 3p 6 4s 1 3d 5 and Cu 1s 2 2s 2 2p 6 3s 2 3p 6 4s 2 3d 9 becomes Cu 1s 2 2s 2 2p 6 3s 2 3p 6 4s 1 3d 10

73. Problems: 1. Write the electron configurations for phosphorus and molybdenum. Then draw the aufbau diagrams for these elements. 2. Write the complete electron configurations for magnesium, sulfur, and potassium. Then write their electron configurations using the symbols for the noble gases. 3. What element is represented by [Ne]3s 2 3p 6 ? 4. Determine the electron configuration for the last SUBLEVEL of the following elements: S, Pt, Sr, K, and Al.

74. 5. The an unknown element has an electron configuration of 1s 2 2s 2 2p 6 3s 2 3p 4. A. What is the element? B. What does the superscript 6 refer to? C. What does the letter s refer to? D. What does the coefficient 3 refer to? 6. Write the electron configuration for calcium, a nutrient essential to healthy bone growth and development. 7. Write the electron configuration for copper, which is used in pennies.

75. 8. Use the symbols for the noble gases to write the electron configurations for the following elements: A. ZrB. UC. Rn 9. Write the electron configuration and draw the orbital diagrams for the following elements: A. CarbonB. SilverC. Aluminum

76. VOCABULARY Electron configuration Atomic number Energy level Valence level Sublevel s,p,d,f Orbital Spin Proton Electron Spherical Two-lobed Dumbell-shaped Aufbau principle Pauli’s exclusion principle Hund’s rule

77. Be able to: Describe the levels, sublevels, and orbitals. Recreate the aufbau order from the periodic chart Write a complete EC and EC with a noble gas core for any element Determine the last sublevel, and number of electrons there from a position on a periodic chart Identify a position on the chart and the element from an EC Fill out an aufbau diagram for any element

78. Trends in the Periodic Chart …since the position on the chart indicates electrons, and electrons are responsible for physical and chemical properties…

79. …the position on the periodic chart indicates the physical and chemical properties of elements! Opposite charges attract– electrons are attracted by the protons in the nucleus

80. Simple Valence electrons –The representative (tall) columns represent the number of valence electrons –Transition elements have only two valence electrons, but have a part-filled d sublevel

82. Simple Ionization pattern Metals - have only a few valence electrons -lose these electrons, empty their valence level -form positive ions

83. Simple Ionization pattern Non-metals have -more valence electrons -gain electrons to fill valence level -form negative ions

85. Medium Atomic size In a column, a lower row indicates an extra energy level Outer energy levels are larger The largest atom in a column is the bottom element

86. Medium Ionization energy —the energy required to remove an electron X + IE  X + + e - Outer energy levels are farther from the nucleus It is easier to remove an electron from a larger energy level The lowest ionization energy is at the bottom of the column

87. Medium Electronegativity —the attraction an atom has for a shared pair of electrons See IE—the highest electronegativity is at the top

88. Medium Electron affinity —attraction an atom has for an electron from the outside X + e -  X - + EA See e-neg—the highest electron affinity is at the top

89. One moment… As you go across a row, you get more protons in the nucleus They attract the electrons better Each energy level gets smaller

90. Hard Atoms get smaller as you go across a row Ionization energy gets larger Electronegativity gets larger Electron affinity gets larger --All because there are more protons--

91. Recap Atomic size INCREASES as you go down and left

92. Recap Electronegativity, ionization energy, and electron affinity INCREASE as you go up and right

93. Pop Quiz Which element on the entire periodic chart is the largest? Smallest? Which element on the entire periodic chart has the largest IE? Smallest?

94. Pop Quiz Which element on the entire periodic chart has the largest e-negativity? Smallest? Which element on the entire periodic chart has the largest EA? Smallest?

95. Pop Quiz Who’s your favorite pop star?

96. Which has the greatest / least: Size, IE, EA, e-neg? C Sn I F

97. The diagonal effect Of the previous four elements, the ones in the same row and column are easy, right? What can you say about carbon and iodine? They might be just about the same!

98. The metal/nonmetal line Diagonal effect! (due to electronegativity or EA)

99. Hard (cont’d) Ionic radius Negative ions are (way!) larger than their atom Positive ions are (way!) smaller than their atom

100. Which has the largest / smallest ion? Li K Ca Be

101. Which has the largest / smallest ion? S Te I Cl

102. Which has the smallest / largest ion? Mg Sr Te S

103. Which has the smallest / largest ion? +2-2 Mg Sr Te S

104. Hard (cont’d) Second and third ionizations If you ionize an atom, you make a (+) ion It’s harder to ionize it again It gets way harder after you empty the valence level

105. Hard (cont’d) First, second, and third ionization energies X + IE  X +1 + e - X +1 + IE 2  X +2 + e - X +2 + IE 3  X +3 + e -

106. Shielding Shielding –weakening of attraction due to electrons interfering with attraction of the nucleus Shielding increases a little as you go across a period (not as much as attraction) Shielding jumps tremendously as you start a new energy level

107. Remem-mem-mem… Ionic radius Negative ions are (way!) larger than their atom Positive ions are (way!) smaller than their atom

108. Remem-mem-mem… Ionic radius Negative ions are (way!) larger than their atom …due to shielding by the extra electrons Positive ions are (way!) smaller than their atom …because they have lost shielding or shielded electrons

109. Disclaimer Noble gasses have no electronegativity— they don’t share electrons Noble gasses have no electron affinity— they don’t gain electrons Most metals have no electron affinity— they don’t gain electrons

113. Ionization Energies in kJ/mol 12345 H 1312 He 23725250 Li 520729711810 Be 89917571484521000 B 800242636592502032820 C 108623524619622137820 N 14022855457674739442 O 131433885296746710987 F 168033756045840811020 Ne 208039636130936112180 Na 49645636913954113350 Mg 73714507731 1054513627

114. Ionization Energies in kJ/mol 12345 H 1312 He 23725250 Li 520729711810 Be 89917571484521000 B 800242636592502032820 C 108623524619622137820 N 14022855457674739442 O 131433885296746710987 F 168033756045840811020 Ne 208039636130936112180 Na 49645636913954113350 Mg 73714507731 1054513627

115. Size of metal atoms

116. Size of Atoms (radius, nm)

119. Size of Anions

120. A positive charge is worth about three energy levels!

121. Size of Cations

122. Electron Affinity*, Electronegativity*, Ionization energy

123. Size

124. Atomic number, shielding, diagonal effect

125. Th-th-that’s all, folks.