Chemistry CP
Review Sheet—Atomic Structure
Name:
Section:
After studying chapters 3 and 4, you should be able to:
• Explain the law of conservation of mass, the law of definite proportions, and the law of
multiple proportions.
• Summarize the five essential points of Dalton’s atomic theory.
• Distinguish among protons, neutrons, and electrons in terms of their relative masses and
charges.
• Explain the structure of an atom, including the location of the proton, neutron, and electron
with respect to the nucleus.
• Explain how atomic number identifies an element.
• Summarize the observed properties of cathode rays that led to the discovery of the electron.
• Summarize Rutherford’s experiment that led to the discovery of the nucleus.
• Explain how isotopes of an element differ.
• Explain, using the concept of isotopes, why the atomic masses of elements are not whole
numbers.
• Infer the number of protons, electrons, and neutrons using the atomic number and mass
number of an element or ion.
• Discuss the dual wave-particle nature of light.
• Explain the relationship between frequency, wavelength, and energy of light.
• Compare and contrast the Bohr model and the quantum model of the atom.
• Relate the number of sublevels corresponding to each of an atom’s main energy levels, the
number of orbitals per sublevel, and the number of orbitals per main energy level.
• Apply the Aufbau principle, the Pauli Exclusion Principle, and Hund’s Rule to write the
electron configurations of the elements.
• Explain the origin of the atomic emission spectrum of an element.
Problems
1. Identify the law that is depicted by the following models. Give reasons to justify your choice.
Who is credited with the discovery of each law?
a.
1 O2 molecule + 2 H2 molecules à 2 H2O molecules
2 O2 molecules + 4 H2 molecules à 4 H2O molecules
b.
c.
1 N2 molecule +
3 H2 molecules à
2 NH3 molecules
m = 28.02 amu m = 6.06 amu
m = 34.08 amu
1 C atom + 1 O2 molecule à 1 CO2 molecule
2 C atoms + 1 O2 molecule à 2 CO molecules
2. Explain the relationship between each law below and Dalton’s atomic theory.
a. Law of multiple proportions
b. Law of conservation of mass
c.
Law of definite composition
3. Which wave shown below resulted from the larger quantum jump? Explain how you arrived
at your answer.
4. How many different energy quanta were released by the element producing the bright-line
spectrum shown below? How do you know this?
5. Which guideline, Hund’s rule or Pauli’s exclusion principle, is violated in the following orbital
diagrams?
6. List the element represented by each of the following electron configurations.
2
2
6
1
a. 1s 2s 2p 3s
2
2
6
2
6
2
6
2
2
6
2
6
2
10
2
1
b. 1s 2s 2p 3s 3p 4s 3d
c.
6
2
1
1s 2s 2p 3s 3p 4s 3d 4p 5s 4d
2
d. [Rn] 7s 5f 6d
2
10
4
e. [Kr] 5s 4d 5p
7. Refer to the periodic table of elements to answer the following questions.
a. What is the atomic number of silicon?
b. How many electrons does a neutral atom of silicon have?
c.
What is the atomic mass of chlorine?
d. How many protons does a neutral atom of chlorine have?
e. How many neutrons does the sulfur isotope sulfur-34 have?
f.
How many neutrons does the sulfur isotope sulfur-36 have?
g. How many electrons does argon have in its 3p energy level?
h. How many electrons does sulfur have in its 3p energy level?
8. Complete the following table.
Protons
Tin-120
Boron-11
Gallium-69
Sulfur-35
Radium-228
2+
Ca
Cl
Neutrons
Electrons
Mass number
40
35
9. Explain what information about orbitals is given by n, the principal quantum number.
10. Draw s, p, and d orbitals. How many of each are present in an energy level?
11. Use orbital notation to write electron configurations for the following elements.
a. Calcium
b. Phosphorus
c.
Sulfur
d. Bromine
e. Manganese
12. Use noble gas notation to write electron configurations for the following elements.
a. Iron
b. rubidium
13. Rubidium has two naturally occurring isotopes. The relative abundance of rubidium-85 is
72.17%; its atomic mass is 84.91 amu. The relative abundance of rubidium-87 is 27.83%; its
atomic mass is 86.91 amu. Determine the average atomic mass of rubidium.
14. List the element represented by each of the following orbital diagrams.