Name
Date
Class
MODELS OF THE ATOM
Section Review
Objectives




Identify inadequacies in the Rutherford atomic model
Identify the new assumption in the Bohr model of the atom
Describe the energies and positions of electrons according to the quantum mechanical model
Describe how the shapes of orbitals at different sublevels vary
Vocabulary
 energy levels
 quantum
 quantum mechanical model
 atomic orbital
Part A Completion
Use this completion exercise to check your understanding of the concepts and terms that are introduced in this
section. Each blank can be completed with a term, short phrase, or number.
The chemical properties of atoms, ions, and molecules are
1
related to the arrangement of the _______
within them.
2
The first modern atomic theory, proposed by _______,
1.
2.
3.
portrayed the atom as a solid, indivisible mass. After the discovery
4.
3
of the electron by _______,
the atomic model was revised to
5.
4
include them. J.J. Thomson’s model is referred to as the _______
6.
5
model. Rutherford pictured the atom as a dense _______
7.
surrounded by electrons. In the Bohr model, the electrons move in
8.
6
7
_______
paths. The _______
model is the modern description of the
8
electrons in atoms. This model estimates the _______
of finding an
electron within a certain volume of space surrounding the nucleus.
Part B True-False
Classify each of these statements as always true, AT; sometimes true, ST; or never true, NT.
9. Electrons must have a certain minimum amount of energy called a quantum in order to move from one
energy level to the next higher energy level.
10. The electron probability clouds for atomic orbitals are spherical in shape.
Chapter 5 Electrons in Atoms
105
Name
Date
Class
11. The number of sublevels in an energy level is equal to the square of the principal quantum number of that
energy level.
12. The maximum number of electrons that can occupy the fourth principal energy level of an atom is 32.
13. The higher the energy level occupied by an electron the more energetic it is.
14. The principal quantum number equals the number of sublevels within that principal energy level.
Part C Matching
Match each description in Column B to the correct term in Column A.
Column A
Column B
15. quantum
a. a region in space around the nucleus of an atom where an electron is
likely to be moving
16. atomic orbitals
b. the regions around the nucleus within which the electrons have the
highest probability of being found
17. energy level
c. the amount of energy required to move an electron from its present
energy level to the next higher one
18. quantum mechanical
model
d. the modern description of the behavior of electrons in atoms
Part D Questions and Problems
Answer the following in the space provided.
19. Summarize the development of atomic theory.
20. How many orbitals are in each of the following sublevels?
a. 4p sublevel
b. 3d sublevel
c. 4f sublevel
d. 2s sublevel
106
Core Teaching Resources
Name
Date
Class
ELECTRON ARRANGEMENT IN ATOMS
Section Review
Objectives
 Describe how to write the electron configuration for an atom
 Explain why the actual electron configurations for some elements differ from those predicted by the Aufbau
principle
Vocabulary
 electron configurations
 Aufbau principle
 Pauli exclusion principle
 Hund’s rule
Part A Completion
Use this completion exercise to check your understanding of the concepts and terms that are introduced in this
section. Each blank can be completed with a term, short phrase, or number.
The ways in which electrons are arranged around the nuclei
1.
1
of atoms are called _______.
The _______
2
describes the
2.
sequence in which orbitals are filled. The various orbitals
3.
within a sublevel of a principle energy level are always of
4.
_______
3
energy. The _______
4
principle states that a maximum
5.
5
of only _______
electrons can occupy each orbital. To occupy
6.
6
the same orbital, two electrons must have _______
spins.
7.
Hund’s rule states that the electrons pair up only after each
8.
7
orbital in a sublevel is occupied by _______
When using the
9.
shorthand method for showing the electron configuration of an
10.
9
atom, _______
are used to indicate the number of _______
8
occupying each sublevel.
Correct electron configurations can be obtained by using
the Aufbau diagram for the elements up to and including
10
vanadium. _______
and copper are exceptions to the Aufbau
principle.
Chapter 5 Electrons in Atoms
107
Name
Date
Class
Part B True-False
Classify each of these statements as always true, AT; sometimes true, ST; or never true, NT.
11. The orbitals of a principal energy level are lower in energy than the orbitals in the next higher principal
energy level.
12. The configuration 3d44s2 is more stable than the configuration 3d54s1.
13. As many as four electrons can occupy the same orbital.
14. The Pauli exclusion principle states that an atomic orbital may describe at most two electrons.
15. The electron configuration for potassium is 1s22s22p63s23p64s1.
16. The electron configuration for copper is 1s22s22p63s23p64s23d9.
Part C Matching
Match each description in Column B to the correct term in Column A
Column A
17. electron configuration
18. Aufbau principle
Column B
a. When electrons occupy orbitals of equal energy, one
electron enters each orbital until all the orbitals contain
one electron with parallel spins.
b. An atomic orbital may describe at most two electrons.
19. Pauli exclusion principle
c. 1s22s22p6
20. Hund’s rule
d. Electrons enter orbitals of lowest energy first.
21. neon
e. the most stable arrangement of electrons around the
nucleus of an atom
Part D Questions and Problems
Solve the following problem in the space provided.
22. Write the electron configurations for the following atoms.
____________________
b. S ____________________
a. C
23. Identify the elements described below:
a. Contains a full third energy level.
b. Contains the first p electron.
108
Core Teaching Resources
____________________
d. Ar ____________________
c. K
Name
Date
Class
PHYSICS AND THE QUANTUM
MECHANICAL MODEL
Section Review
Objectives




Describe the relationship between the wavelength and frequency of light
Explain how the frequencies of light are related to changes in electron energies
Distinguish between quantum mechanics and classical mechanics
Identify the cause of the atomic emission spectrum
Vocabulary




amplitude
wavelength ()
frequency ()
hertz (Hz)




electromagnetic radiation
spectrum
atomic emission spectrum
ground state
 photons
 Heisenberg uncertainty principle
Key Equations
 c = 
E=h
h

mv
Part A Completion
Use this completion exercise to check your understanding of the concepts and terms that are introduced in this
section. Each blank can be completed with a term, short phrase, or number.
According to quantum mechanics, the motions of subatomic
1.
particles may be described as _______.
The frequency and
1
2.
wavelength of all waves are _______
related.
2
3.
Every element emits _______
if it is heated by passing an
3
4.
electric discharge through its gas or vapor. Passing this emission
5.
through a prism gives the _______
of the element.
4
6.
The quantum concept developed from Planck’s studies of
7.
and _______
Einstein's explanation of the _______effect.
5
6
Planck showed that the amount of radiant energy absorbed or
emitted by a body is proportional to the _______
of the
7
radiation.
.
Chapter 5 Electrons in Atom 109
Name
Class
Date
Part B True-False
Classify each of these statements as always true, AT; sometimes true, ST; or never true, NT.
8. The speed of light is a constant that can be obtained by dividing the frequency of light by its wavelength.
9. The amplitude of a wave is the distance between the crests.
10. The energy of a body can change only in small discrete units.
11. The position and velocity of an electron in an atom can be determined with great certainty.
12. The photoelectric effect will occur no matter what frequency of light strikes a metal.
Part C Matching
Match each description in Column B to the correct term in Column A.
Column A
Column B
13. photons
a. predicts that all matter exhibits wavelike motions
14. de Broglie’s equation
b. the distance between two consecutive wave crests
15. visible light
c. light quanta
16. ground state
d. the lowest energy level for a given electron
17. wavelength
e. example of electromagnetic radiation
Part D Questions and Problems
Answer the following in the space provided.
18. What is the frequency of radiation whose wavelength is 2.40  10–5 cm?
19. Apply quantum theory to explain the photoelectric effect.
110
Core Teaching Resources