A.P. Chemistry – Chapter 7: Atomic Theory and Periodic Table
7.1 Review of the Atom
7.1 Electromagnetic Radiation
7.2 The Nature of Matter
7.3 The Atomic Spectrum of Hydrogen
7.4 The Bohr Model
7.5 – 7.7 Quantum Mechanics
7.8 Pauli Exclusion Principle
7.11 Aufbau Principle and the Periodic Table
7.12 Periodic Trends
Test: Tuesday, October 26
I. What do we already know about atoms?
A. Three subatomic particles are
1.
2.
3.
B. The center of the atom is the ________________________
1.
2.
3.
C. The idea of QUANTA
7.1 Electromagnetic Radiation – Light as a _______________________
Wave properties of light:
Parts of a wave:
1. Wavelength
2. Frequency
3. Period
4. Amplitude
Light Equation:
where c =
Example 1: Calculate the frequency of red light of wavelength 6.50 x 102 nm.
Example 2: A microwave oven uses radiation with a frequency of 2.45 x 109 s-1. What is the
wavelength of this radiation?
7.2 The Nature of Matter
Max Planck (1858-1947) – Important Conclusions
1. Energy is ___________________ This means
that energy comes in discrete units called
___________.
2. Light (and all electromagnetic radiation) travels
as a ___________________ and as a __________.
A particle of light is called a ________________.
Energy of a photon:
Example 1: What is the energy of a photon corresponding to
Microwave radiation of frequency 1.145 x 1010/s
Example 2: What is the energy involved in blue light having a
wavelength of 450 nm?
where h =
BOHR’s Model of the Atom: He proposed that
Two fundamental ideas from Bohr’s study of Hydrogen:
1. Energy Level postulate
2. Transitions between energy levels:
a. Moving from a lower to higher energy level
b. Moving from a higher to a lower energy level
3.
Example 1: Calculate the energy required to excite the hydrogen
electron form level n=3 to level n=2. Also calculate the
wavelength of light that must be absorbed by a hydrogen atom in
its ground state to reach this excited state.
Example 2: Calculate the energy required to remove the electron from a hydrogen atom in its
ground state.
Quantum Mechanics
Quantum Numbers:
1. Principle Quantum Number Symbol:
Values:
2. Azimuthul Quantum Number Symbol:
Values:
3. Magnetic Quantum Number Symbol:
Values:
4. Spin Quantum Number Symbol:
Values:
5. Examples:
1. For principle quantum level n = 5, determine the number of allowed subshells (the
different values of l), and give the designation of each.
2. State whether each of the following sets of quantum numbers is permissible for an
electron in an atom. If a set is not permissible, then explain why.
1
2
1
b. 3, 1, -2, 2
a. 1, 1, 0, +
c. 2, 1, 0, +
d. 2, 0, 0, 1
1
2
Electron Configurations
Pauli Exclusion Principle
Aufbau Principle
Hund’s Rule
Examples
Exceptions
Periodic Trends
I. Atomic Radius
A. Down a groupB. Across a periodC. Reasons:
D. Example AP question:
1. Account for the following observation in terms of atomic or quantum theory
a. Atomic size decreases from Na to Cl in the periodic table.
2. List the following atoms in order of increasing atomic radius:
a. Cr, Ni, Kr, Ga, K
b. P, As, F, Hg, Fr
II. Ionic Radius
A. Cations-
B. Anions-
C. Example AP Exam Question
1. Which ion, Mg2+ or Na1+, would you expect to have the smaller radius? Justify your answer.
III. Ionization Energy
A. Across a period
B. Down a group
C. Reasons
E. Second and Third Ionization Energies
F. Example AP Exam Questions:
1. Using principles of atomic and molecular structure and the information in the table
below, answer the following questions about atomic fluorine, oxygen, and xenon.
Atom
First Ionization Energy
(kJ mol-1)
F
1,681.0
O
1,313.9
Xe
?
a. Write the equation for the ionization of atomic fluorine that requires 1,681.0 kJ mol-1.
b. Account for the fact that the first ionization energy for atomic fluorine is greater than the first
ionization energy for atomic oxygen. (You must discuss both atoms in your response).
c Predict whether the first ionization energy of Xe is less than, greater than, or equal to the first
ionization energy of atomic fluorine. Justify your prediction.
2.
Element 1
First
Ionization Energy
kJ mol-1
1,251
Second
Ionization Energy
kJ mol-1
2,300
Third
Ionization Energy
kJ mol-1
3,820
Element 2
496
4,560
6,910
Element 3
738
1,450
7,730
Element 4
1,000
2,250
3,360
The table above shows the first three ionization energies for four elements in the third period of
the periodic table. The elements are numbered randomly. Use the information in the table to
answer the following questions.
(a) Which element is most metallic in character? Explain your reasoning.
(b) Identify element 3. Explain your reasoning.
(c) Write the complete electron configuration for an atom of element 3.
(d) What is the expected oxidation state for the most common ion of element 2?
(e) What is the chemical symbol for element 2?
(f) A neutral atom of which of the four elements has the smallest radius?
IV. Electron affinity
A.
Definition
B.
Down
C.
Across
Extra Practice:
1. Fill in the missing information:
Energy (Joules)
Wavelength-λ
(meters)
6.3 x 10-19 J
Frequency –ν (s-1)
2.4 x 10-7 m
100 s-1
1.5 x 10-14 J
10
2.2 x 1013 s-1
525 nm
2. For each of the elements listed below, complete the following:
a. long hand electron configuration
b. orbital diagram (boxes with arrows)
c. short hand electron configuration
1. Na
2. K
3. B
Color of
Light/type of
electromagnetic
radiation
4. Al
5. Ar
6. Br
7. Zn
8. Ni
9. Ca2+
10. N3-
Part C: Periodicity
Name____________________
2. List the following atoms in order of increasing electronegativity:
a. Cr, Ni, Kr, Ga, K
b. P, As, F, Hg, Fr
3. List the following atoms in order of increasing ionization energy:
a. Cr, Ni, Kr, Ga, K
b. P, As, F, Hg, Fr
4. Why are alkali metals stored in kerosene or mineral oil? Why are they not
allowed to sit out in the air?
5. The Mg+2, and the Na+1 ions each have ten electrons surrounding the nucleus.
Which ion would you expect to have the smaller radius?