CHEM 120 MIDTERM EXAM
1. Question : (TCO 3) The maximum number of electrons that may reside in the n=1
energy level is
Student Answer:
2.
3.
8.
10.
18.
Instructor Explanation: Chapter 3
2. Question : (TCO 3) How many electrons are in a potassium atom?
Student Answer:
15
19
23
39
84
Instructor Explanation: Chapter 3
3. Question : (TCO 3) Which is an impossible electron configuration?
Student Answer:
1s2 2s2
1s2 2s2 2p4
1s3 2s2 2p4
1s2 2s2 2p4 3s1
1s2 2s2 2p4 3s2
, Instructor Explanation: Chapter 3
4. Question : (TCO 3) The ground element with the ground state electron
configuration of 1s2 2s2 2p6 3s2 is
Student Answer:
Mg.
Ca.
Mn
Na.
Ne.
Instructor Explanation: Chapter 3
5. Question : (TCO 3) Which substance has ionic bonds?
Student Answer:
K2S
CO3
CCl4
N2
NH3
Instructor Explanation: Chapter 4
6. Question : (TCO 3) A nitride ion is _____.
Student Answer:
N+
N2-
N
N3+
N3-
Instructor Explanation: Chapter 4
7. Question : (TCO 3) The correct name for the compound N 2O3 is _____.
, Student
Answer: dinitrogen trioxide
nitrogen oxide
nitrogen trioxide
dinitride trioxide
dinitrogen oxide
Instructor Chapter 4; According to the rules of naming for covalent compounds, the correct
Explanation: name of N2O3 is dinitrogen trioxide. The first nonmetal is named by its elemental
name. The second nonmetal is named by its elemental name plus -ide. There are 2
nitrogens, so you add the prefix di-. There are 3 oxygens, so you add the prefix tri-.
8. Question : (TCO 4) If a central atom has a total of three groups and no lone pairs
attached to it, the geometry about the central atom is _____.
Student Answer:
linear
triangular
pyramidal
tetrahedral
None of the above
Instructor Explanation: Chapter 4
9. Question : (TCO 4) Which of the following is the electron dot structure for
hydrogen, H2?
10. Question : (TCO 4) Which substance has polar covalent bonds?
Student Answer:
SO2
N2
Cl2
CaO
None of the above
Instructor Explanation: Chapter 4
1. Question : (TCO 3) The maximum number of electrons that may reside in the n=1
energy level is
Student Answer:
2.
3.
8.
10.
18.
Instructor Explanation: Chapter 3
2. Question : (TCO 3) How many electrons are in a potassium atom?
Student Answer:
15
19
23
39
84
Instructor Explanation: Chapter 3
3. Question : (TCO 3) Which is an impossible electron configuration?
Student Answer:
1s2 2s2
1s2 2s2 2p4
1s3 2s2 2p4
1s2 2s2 2p4 3s1
1s2 2s2 2p4 3s2
, Instructor Explanation: Chapter 3
4. Question : (TCO 3) The ground element with the ground state electron
configuration of 1s2 2s2 2p6 3s2 is
Student Answer:
Mg.
Ca.
Mn
Na.
Ne.
Instructor Explanation: Chapter 3
5. Question : (TCO 3) Which substance has ionic bonds?
Student Answer:
K2S
CO3
CCl4
N2
NH3
Instructor Explanation: Chapter 4
6. Question : (TCO 3) A nitride ion is _____.
Student Answer:
N+
N2-
N
N3+
N3-
Instructor Explanation: Chapter 4
7. Question : (TCO 3) The correct name for the compound N 2O3 is _____.
, Student
Answer: dinitrogen trioxide
nitrogen oxide
nitrogen trioxide
dinitride trioxide
dinitrogen oxide
Instructor Chapter 4; According to the rules of naming for covalent compounds, the correct
Explanation: name of N2O3 is dinitrogen trioxide. The first nonmetal is named by its elemental
name. The second nonmetal is named by its elemental name plus -ide. There are 2
nitrogens, so you add the prefix di-. There are 3 oxygens, so you add the prefix tri-.
8. Question : (TCO 4) If a central atom has a total of three groups and no lone pairs
attached to it, the geometry about the central atom is _____.
Student Answer:
linear
triangular
pyramidal
tetrahedral
None of the above
Instructor Explanation: Chapter 4
9. Question : (TCO 4) Which of the following is the electron dot structure for
hydrogen, H2?
10. Question : (TCO 4) Which substance has polar covalent bonds?
Student Answer:
SO2
N2
Cl2
CaO
None of the above
Instructor Explanation: Chapter 4
