1. HONORS CHEMISTRY
September 9, 2013

2. Atomic History Democritus Dalton JJ Thomson Rutherford Chadwick Bohr
Matter is composed of empty space in which atoms move
Elements consist of atoms and compounds are collection of atoms
“Plum pudding model” : Atoms contain negative particles called electrons
Alpha particles, positive charge with a mass 7500x of electron. Proved the plum pudding model was wrong. Nucleus center ( +) and tiny electrons moved in space around it.
Discovered neutrons (slightly more massive than a proton).
Electrons are in circular paths depending on their energy levels

3. Atomic History De Broglie Schrodinger Millikan Moseley
electrons move in waves rather than straight circular paths
Wave Mechanical Model or Quantum Mechanical Model. Furthered De Broglie’s idea of waves by stating that electrons are in clouds but in certain energy region
Oil drop experiment: discovered that atoms had positive and negative charges and that they equal each other
Helped to arrange atoms in the periodic table. Atoms were arranged in increasing atomic number using wavelengths and
x-rays

4. Atoms, Isotopes and Ions
How do atoms of different elements differ?

5. The Modern View of Atomic Structure
What are the particles that make up an atom and how do they differ from one another?
proton mass = 1 amu charge = +1
neutron mass = 1 amu charge = 0
electron mass = “0” amu charge = -1
1 amu = x kg
02m14an1
1/1840
atoms have equal numbers of protons and electrons so they are electrically neutral

6. C Atomic Number 6 Carbon Atomic number Number of protons in an atom
Identifies the element C 6
Carbon

7. Atomic Number Use the Periodic Table to complete the following.
1. What element has the atomic number 18?
2. What element has 35 protons?

8. How are atoms of one element different from those of another element?
They have different numbers of these subatomic particles.
Atomic Number H 1
Hydrogen
Chemical Symbol
Element Name
Average Atomic Mass

9. Isotopes How do we distinguish between atoms?
Do all atoms of an element have the same composition?
Heavy Water and Water Ice Cube in water

10. Isotopes
What implication does this have for the masses of atoms?
Average atomic mass
Isotopes differ only in the number of Neutrons
Difference is shown by their mass numbers
Notation: superscript for mass number, which is the sum of the number of protons and neutrons
Notation: subscript for atomic number, which is the number of protons (or electrons)
73Li Be B

11. Nuclear Particles
How many of each particle (protons, neutrons and electrons) are in these atoms?
7635 Br Br Br
147N N
188O 178O O 158O

12. Ions
When an atom loses or gains electrons and acquires a net electrical charge.
Gain electrons – negative ion - anion
Lose electrons – positive ion - cation
Mg2+ Mg

13. Ions Charge of ion = # of protons - # of electrons
How many protons, neutrons and electrons does 4120Ca2+ have?
How many protons, neutrons and electrons does 7835Br - have?

14. Think-Pair-Share
Atomic Structure Worksheet

15. Closure 1. How many protons, neutron and electrons does Mg have?
does 74Be -2 have?

16. HONORS CHEMISTRY
September 10, 2013

17. Brain Teaser Place homework on your desk
How many protons, neutrons and electrons does 3211Na +1 have?
Who developed the planetary model of the atom based on quantum energy levels
Who discovered that most of the atom’s mass is located in the nucleus of an atom and the atom is mostly empty space
Who discovered the electrons and developed the plum pudding model of the atom

18. Agenda Brain Teaser Grade Homework: Atomic Structure Worksheet Notes:
Wave and Particle Nature of Light
Line Spectra
Quantum Theory
Bohr Models
Homework
Bohr’s Model Worksheet/Isotope Worksheet

19. Review (Insert) Mass of Proton: 1.67 x 10-24 grams = 1 amu
Mass of Neutron: 1.67 x grams = 1 amu
Mass of Electron: 9.1 x grams (essentially zero)

20. Unit 3 Light and Quantized Energy Electron Configuration
Objective:
Learn how electrons are arranged in an atom and how that arrangement plays a role in their chemical behavior

21. How do we know what makes up an atom?

22. The Atom is a Scientific Model
With the scanning tunneling microscope we can see atoms, but we still cannot see their internal structure.
Scientific models are created by experiments, but are often modified.
There may be flaws in the current model.

23. What do atoms look like?
See the electron microscope image of the molecular art drawn with gold (Au) atoms.
See the image of graphite. Are these images proof of atoms? How do we see atoms?
nickel
benzene
graphite

24. How do we know what makes up atoms?

25. Cathode Ray Tubes
Why does the beam bend?

26. Gold Foil Experiment
Examine the diagram of Rutherford’s alpha ray experiment. What is the implication of this experiment?

27. Line Spectra Bright Line Spectra
Bright Line Spectra
Lines of color produced by light emitted from heating substances and passing them through a prism
Fingerprints of elements
Researchers can determine values of energy levels in atoms
Used to identify different elements

28. Observation of unique line spectra led to Quantum Theory
E=hν
Fourth
Third
Second
First
Nucleus

29. Demo Point Spectroscope towards the fluorescent light bulb
Observe the bright line spectrum of mercury and phosphorous

30. Where all of this has led to
Bohr Model – did some good things but it is not the whole truth.

31. Some Questions
Color arises from electrons shifting from one orbital to another of different energy
Ground state and excited state
What shift would give rise to emission of light? to absorption of light?

32. Where all of this has lead to
Quantum Model

33. What is the Quantum Mechanical Model?
It predicts quantized energy levels for electrons, like the Bohr model.

34. What is Quantum Theory?
It does not describe the exact path that electrons take around the nucleus of an atom, but is concerned with the probability of an electron being in a certain place.

35. Nucleus

36. Orbitals Areas where an electron can be found
Can have up to two electrons
Fuzzy boundaries  “Electron Cloud”

37. The Closed Sphere Model
For convenience
Shows where the electron is 90% of the time

38. The Heisenberg Uncertainty Principle
You can never know exactly where an electron is if you know exactly how fast it is moving.
You can never know exactly how fast an electron is moving if you know exactly where it is.

39. Bohr Diagram Practice Worksheet

40. THE END

41. HONORS CHEMISTRY
September 12, 2012

42. Brain Teaser Place Homework on your desk
Write the complete symbol from the given information below:
20 protons, 22 neutrons, 18 electrons
15 protons, 17 neutrons, 18 electrons
17 protons, 18 neutrons, 17 electrons
How many protons, neutrons, and electrons are there for each of the following atoms or ions?
12 B+3
80 35 Br

43. Agenda Brain Teaser Grade Homework Bright Line-Emission Spectra
Practice Quiz
Homework
Study for Quiz (Friday)

44. Grade Homework Bohr Diagram Worksheet Isotopes Worksheet
Look for patterns:
Period
Group
Label Periodic Table
Isotopes Worksheet

45. Bright Line Emission Spectra Lab Activity
Objective
Identify different metals through flame tests and using bright line emission spectra

46. Background Light = Electromagnetic radiation
Frequency of light relates to energy (Diagram)
Higher Frequency = Higher Energy
Frequency and Color are related
(Low)Radio, M, IR, Visible, UV, X-Ray, Gamma Ray(High)
Visible Light: (Lower) R O Y G B I V (Higher)
White light has all the colors
Prism/Diffraction Gratin  Breaks up colors
Gaseous element contained in a tube  energize it with electricity  glow/gives off visible light

47. Background Electrons absorbing energy “excited”
Electrons giving off energy  Gives off light
All atoms have all energy levels but they may not have e- on them. (Diagram)
e- jumps to a higher energy level “excited” state
e- will give off energy/falls back down  give off visible light (lowest possible energy level = ground state)
Energy of photon is proportional to the color
Some energy are given off as invisible spectrum like IR or UV
Red photon is lower in energy compared to blue photon

48. Background
Tube filled with Ne, H, or He (discrete lines)  Atomic Emission Spectra
e- cannot have any amount of energy but only certain amount of energy (no in b/w color)
Evidence: only certain colors are given off e- exist only at certain distances from the nucleus
Every element has a unique emission spectrum because it has different electron configuration
Emission Spectra as a fingerprint of elements
Applications: Astrophysics or Forensics

49. Background
Electrons are only allowed in certain energy levels, only have a certain amount of energy, can only give off a certain amount of energy (quantized energy)
Different elements have different frequencies and they give off a different set of colors

50. Line Spectra

51. Observation of unique line spectra led to Quantum Theory
E=hν
Fourth
Third
Second
First
Nucleus

52. Element Finger Print
07m07an1

53. Spectroscopes Practice using the Spectroscopes What do you see?
Where is it coming from?

54. Lab Line Spectrum Station Rotation
At each Station
Spectra
Observe through spectroscope
Record measurements and notes
Switch roles to judge precision of observation
Data Analysis
Compare spectra to various reference sources
Identify substance
Work on study questions

55. Lab Rotation
Identify the emission spectra for 5 gas tubes and 4 stations for Flame tests
Flame test: Dip the sticks in water and WEAR GOGGLES!
Use colored pencils to mark the reference for each station (Gas Tubes)
Use colored pencils to mark the reference for Flame Tests
Write a qualitative analysis on each emission spectrum

56. Questions?

57. Color Coding the Periodic Table Activity
Read handout
Fill out Family Ties (Student Worksheet)
Homework:
Study for Quiz (Friday)

58. Start

59. Lab Line Spectrum Station Rotation
At each Station
Pair A
Spectra
Observe through spectroscope
Record measurements and notes
Switch roles to judge precision of observation
Pair B
Data Analysis
Compare spectra to various reference sources
Identify substance
Work on study questions

60. Spectroscopes
What do you see?
Where is it coming from?

61. Line Spectra

63. HONORS CHEMISTRY
September 17, 2012

64. Brain Teaser
Explain why each element can produce its own bright line spectrum

65. Agenda Brain Teaser Pre-Test: Periodic Trends Notes:
Bohr’s Model
Orbital Diagrams and Electron Configuration
Practice Writing electron configuration
Homework
Electron configuration worksheet

66. Bohr's Model
Model of electrons in fixed orbits to explain quantization Figure 6.14
Transitions between orbits emits or absorbs light
07m07an1

67. Observation of unique line spectra led to Quantum Theory
E=hν
Fourth
Third
Second
First
Nucleus

68. Orbital Diagrams and Electron Configurations
n = Principle quantum number
Describes the energy level the electron occupies
n = 4
n = 3
n = 2
n = 1

69. Orbital Energy Levels Shape of orbital designated by the letters
s, p, d, f, g
Excited states
Ground state

70. Shapes of Orbitals Shape of orbital designated by the letters
s, p, d, f, g
Orbitals have different shapes

71. s Orbital shape The s orbital has a spherical shape centered around
the origin of the three axes in space.

72. p orbital shape
There are three dumbbell-shaped p orbitals in each energy level above n = 1, each assigned to its own axis (x, y and z) in space.

73. d orbital shapes
Things get a bit more complicated with the five d orbitals that are found in the d sublevels beginning with n = 3. To remember the shapes, think of “double dumbells”
…and a “dumbell
with a donut”!

74. Shape of f orbitals

75. Combination
of electron
microscopy
and x-ray
diffraction
produced
image of
orbitals

76. Sets of Orbitals (Subshells)
Depending on the type of orbital, we find that they occur in sets differing in their orientation in space
s - set of 1
p - set of 3
d - set of 5
f - set of 7

77. Sizes of orbitals Size depends on the value of n
Orbitals with the same n are about the same size

78. Check for understanding
What is the principal quantum number for Ar?
What are the subshells?
How many sets of electrons are found in each subshell?

79. Electron Configurations of Some Atoms
The first ten elements
1s1
1s2
1s2 2s1
1s2 2s2
1s2 2s2 2p1
1s2 2s2 2p2
1s2 2s2 2p3
1s2 2s2 2p4
1s2 2s2 2p5
1s2 2s2 2p6

80. Shorthand Notation for Orbitals
Combinations of first two quantum numbers; number of orbital types equals the shell number (n). 1s
2s, 2p
3s, 3p, 3d
4s, 4p, 4d, 4f
5s, 5p, 5d, 5f, (5g)
6s, 6p, 6d, 6f, (6g, 6h)
(Stop: Period 5)

81. HONORS CHEMISTRY
September 18, 2012

82. Brain Teaser Place Homework on your desk
Write the Electron Configuration for the following elements: Si Co Se

83. Agenda Brain Teaser Grade Worksheet Review Notes: Orbital Diagram
Writing Electron Configuration
Notes: Orbital Diagram
Homework
Short Hand Electron Configuration
Orbital Diagram

84. Grade Homework
Refer to Worksheet (Arrangement of Electrons I)

85. Check for understanding (P6)
What is the principal quantum number for Ar?
What are the subshells?
How many sets of electrons are found in each subshell?

86. Aufbau Principle
Aufbau Principle: start with the nucleus and empty orbitals, then “build” up the electron configuration using orbitals of increasing energy

87. Electron Configurations
Electron Spin and Pauli Exclusion Principle:
Only two electrons can occupy a single orbital and they must have opposite spins

88. Electron Configurations
Hund's Rule:
When filling a subshell, such as the set of 3 p orbitals, place 1 electron in each before pairing up electrons in a single orbital

89. Electron Configurations
Arrangement of electrons in the orbitals is called the electron configuration of the atom
The ground state configuration can be predicted, using the Aufbau Principle, the Pauli Exclusion Principle, and Hund’s Rule.
Electron configurations
Filling _ rules.exe

90. How do we know what the filling order is?
What chemistry tool might we rely on?

91. Electron Configurations and the Periodic Table
Valence electron configurations repeat down a group

92. Ground state electron configurations
Example: Li
atomic number = 3
nucleus has 3 protons
neutral atom has 3 electrons
2 electrons in 1s orbital, 1 electron in 2s orbital 2s 1s

93. Different ways to show electron configuration
Energy level diagram
Box notation   2s 1s 2s 1s
Spectroscopic notation
Li 1s2 2s1
Read this “one s two” not “one s squared”
Write the superscript 1. Don’t leave it blank

94. Practice Review (on separate sheet of paper)
Electron Configuration
Orbital Diagram
Electron configuration worksheet

95. Using the Periodic Table
The last subshell in the electron configuration is one of these
(row #) s (row # – 1) d
(row #) p (row # – 2) f

96. The f-block is inserted into to the d-block

97. Electron configuration of O
Atomic number of O = 8 so neutral atom has 8 e–

98. Electron configuration of Co
Atomic number of Co = 27 so neutral atom has 27 e–

99. Simplifying electron configurations
Build on the atom’s noble gas core
He 1s2
O 1s22s22p4
O [He]2s22p4
Ar 1s22s22p63s23p6
Co 1s22s22p63s23p64s23d7
Co [Ar]4s23d7      1s 2s 2p                1s 2s 2p 3s 3p 4s 3d

100. Noble Gases Far right of the periodic table
These elements are extremely unreactive or inert
They rarely form compounds with other elements

101. Noble Gas electron configurations
What is the electron configurations for Neon
Abbreviated way to write configurations
Start with full outer shell then add on Br Ba

102. Noble Gases
Neon- emits brilliant light when stimulated by electricity – neon signs- 4th most abundant element in the universe.
Helium- light non reactive gas- used balloons- inexpensive, plentiful and harmless
Radon- radioactive gas- can cause cancer- colorless, odorless emitted from for certain rocks underground

104. Why are we doing all of this?
Properties of atoms correlate with the number and energy of electrons
Electron configurations are used to summarize the distribution of electrons among the various orbitals

105. Practice
3-3 Practice
Write the complete electron configurations and noble gas shorthand #1-4

106. Practice
Refer to a periodic table and write the electron configurations of these atoms.
Write the configurations using shorthand notation. Zn I Cs

107. The f-block is inserted into to the d-block

108. Find the electron configuration of Au
Locate Au on the periodic table

109. Find the electron configuration of Au
Au [Xe]
The noble gas core is Xe

110. Find the electron configuration of Au
Au [Xe]6s2
The noble gas core is Xe
From Xe, go 2 spaces across the s-block in the 6th row  6s2

111. Find the electron configuration of Au
Au [Xe]6s24f14
The noble gas core is Xe
From Xe, go 2 spaces across the s-block in the 6th row  6s2
Then detour to go 14 spaces across the f-block  4f14
note: for the f-block, n = row – 2 = 6 – 2 = 4

112. Find the electron configuration of Au
Au [Xe]6s24f145d9
The noble gas core is Xe
From Xe, go 2 spaces across the s-block in the 6th row  6s2
Then detour to go 14 spaces across the f-block  4f14
note: for the f-block, n = row – 2 = 6 – 2 = 4
Finally go 9 spaces into the d-block on the 6th row  5d9
note: for the d-block, n = row – 1 = 6 – 1 = 5

113. Electron configuration of ions
What is an ion?
How many electrons does Cl1- have?
What is the electron configuration for the chloride ion?
How many electrons does Ca2+ have?
What is the electron configuration for the calcium ion?
What do you notice?

114. Practice Draw the orbital diagram for sulfur.
What ion does sulfur want to form and why?
Draw the orbital diagram for Potassium.

115. What does this mean
Properties of atoms correlate with the number and energy of electrons
Atoms like to have full outer shells.

116. Why is this important Valence electrons
Electrons in the outermost energy level
Where all the action occurs

117. Practice
Whiteboard - Atomic Structure (continued)

118. Team Write the electron configuration for silver.
Write the noble gas configuration for silver.
What element has the following electron configuration?
1s22s22p6 3s23p64s23d4

119. Today we use aspects of line spectrum to identify elements, compounds and mixtures?
UV-Vis Spectrometer
Distances and types of stars
Blood test- carbon monoxide poisoning
Mobile weapons detectors
Chlorophyll
119

120. How we determine these energy levels?
120