Review

Name: __________________ Chemistry
Midterm Review
1. Which statement best describes the nucleus of an aluminum
atom?
(1) It has a charge of +13 and is surrounded by a total of
10 electrons.
(2) It has a charge of + 13 and is surrounded by a total of
13 electrons.
(3) It has a charge of -13 and is surrounded by a total of 10
electrons.
(4) It has a charge of -13 and is surrounded by a total of 13
electrons.
2. Which conclusion is based on the “gold foil experiment”
and the resulting model of the atom?
(1) An atom is mainly empty space, and the nucleus has a
positive charge.
(2) An atom is mainly empty space, and the nucleus has a
negative charge.
(3) An atom has hardly any empty space, and the nucleus
has a positive charge.
(4) An atom has hardly any empty space, and the nucleus
has a negative charge.
3. Which symbol represents a particle with a total of 10
electrons?
(1) N (3) Al
(2) N 3+
(4) Al 3+
4. Which subatomic particle has a negative charge?
(1) proton (3) neutron
(2) electron (4) positron
5. Compared to a proton, an electron has
(1) a greater quantity of charge and the same sign
(2) a greater quantity of charge and the opposite sign
(3) the same quantity of charge and the same sign
(4) the same quantity of charge and the opposite sign
6. Which electron configuration represents an atom of
aluminum in an excited state?
(1) 2-7-4 (3) 2-8-3
(2) 2-7-7 (4) 2-8-6
7. What is the charge of the nucleus in an atom of oxygen-17?
(1) 0 (3) +8
(2) –2 (4) +17
8. What is the total number of neutrons in the nucleus of a
neutral atom that has 19 electrons and a mass number of 39?
(1) 19 (3) 39
(2) 20 (4) 58
9. The atomic mass unit is defined as exactly 1/12 the mass of
an atom of
(1) 12
24
6 C (3) 12Mg (2) 14
26
6 C (4) 12Mg 10. Isotopes of an element must have different
(1) atomic numbers (3) numbers of protons
(2) mass numbers (4) numbers of electrons
11. All isotopes of a given element must have the same
(1) atomic mass (3) mass number
(2) atomic number (4) number of neutrons
12. What is the structure of a krypton-85 atom?
(1) 49 electrons, 49 protons, and 85 neutrons
(2) 49 electrons, 49 protons, and 49 neutrons
(3) 36 electrons, 36 protons, and 85 neutrons
(4) 36 electrons, 36 protons, and 49 neutrons
13. Which two notations represent atoms that are isotopes of
the same element?
(1) 121 119
19 19
50 Sn and 50 Sn (3) 8 O and 9 F
(2) 121 121
39 39
50 Sn and 50 Sn (4) 17 Cl and 19 K
14. Which mixture can be separated by using the equipment
shown below?
(1) NaCl(aq) and SiO2 (s)
(2) NaCl(aq) and C6H12O6 (aq)
(3) CO2 (aq) and NaCl(aq)
(4) CO2 (aq) and
C6H12O6 (aq)
15. Element X has two isotopes. If 72.0% of the element has an
isotopic mass of 84.9 atomic mass units, and 28.0% of the
element has an isotopic mass of 87.0 atomic mass units, the
average atomic mass of element X is numerically equal to
(1)
(2)
(3)
(4)
16. What is the total number of electrons found in an atom of
sulfur?
(1) 6 (3) 16
(2) 8 (4) 32

17. The atomic mass of an element is the weighted average of
the
(1) number of protons in the isotopes of that element
(2) number of neutrons in the isotopes of that element
(3) atomic numbers of the naturally occurring isotopes of
that element
(4) atomic masses of the naturally occurring isotopes of
that element
18. The modern model of the atom is based on the work of
(1) one scientist over a short period of time
(2) one scientist over a long period of time
(3) many scientists over a short period of time
(4) many scientists over a long period of time
19. In the wave-mechanical model, an orbital is a region of
space in an atom where there is
(1) a high probability of finding an electron
(2) a high probability of finding a neutron
(3) a circular path in which electrons are found
(4) a circular path in which neutrons are found
20. During a flame test, ions of a specific metal are heated in
the flame of a gas burner. A characteristic color of light is
emitted by these ions in the flame when the electrons
(1) gain energy as they return to lower energy levels
(2) gain energy as they move to higher energy levels
(3) emit energy as they return to lower energy levels
(4) emit energy as they move to higher energy levels
21. Which of these phrases best describes an atom?
(1) a positive nucleus surrounded by a hard negative shell
(2) a positive nucleus surrounded by a cloud of negative
charges
(3) a hard sphere with positive particles uniformly
embedded
(4) a hard sphere with negative particles uniformly
embedded
22. Recovering the salt from a mixture of salt and water could
best be accomplished by
(1) evaporation (3) paper chromatography
(2) filtration (4) density determination
23. Which element is malleable and conducts electricity?
(1) iron (3) sulfur
(2) iodine (4) phosphorus
24. At STP, an element that is a brittle solid and a poor
conductor of heat and electricity could have an atomic
number of
(1) 12 (3) 16
(2) 13 (4) 17
25. What are two properties of most nonmetals?
(1) high ionization energy and poor electrical conductivity
(2) high ionization energy and good electrical conductivity
(3) low ionization energy and poor electrical conductivity
(4) low ionization energy and good electrical conductivity
26. Which substance can not be decomposed by a chemical
change?
(1) Ne (3) HF
(2) N2O (4) H2O Base your answers to questions 27 and 28 on the information
below.
Naturally occurring elemental carbon is a mixture of
isotopes. The percent composition of the two most
abundant isotopes is listed below.
• 98.93% of the carbon atoms have a mass of 12.00
atomic mass units.
• 1.07% of the carbon atoms have a mass of 13.00
atomic mass units.
27. Describe, in terms of subatomic particles found in the
nucleus, one difference between the nuclei of carbon-12
atoms and the nuclei of carbon-13 atoms. The response
must include both isotopes.
28. In the space provided in your answer booklet, show a
correct numerical setup for calculating the average atomic
mass of carbon.
29. Which pair of symbols represents a metalloid and a noble
gas?
(1) Si and Bi (3) Ge and Te
(2) As and Ar (4) Ne and Xe
30. Which element is a solid at STP?
(1) H2 (3) N2 (2) I2 (4) O2 31. Given the particle diagram:
At 101.3 kPa and 298 K, which element could this diagram
represent?
(1) Rn (3) Ag
(2) Xe (4) Kr
32. Which list consists of elements that have the most similar
chemical properties?
(1) Mg, Al, and Si (3) K, Al, and Ni
(2) Mg, Ca, and Ba (4) K, Ca, and Ga
33. Which list of elements contains a metal, a metalloid, and a
nonmetal?
(1) Zn, Ga, Ge (3) Cd, Sb, I
(2) Si, Ge, Sn (4) F, Cl, Br
34. The elements in Period 5 on the Periodic Table are arranged
from left to right in order of
(1) decreasing atomic mass
(2) decreasing atomic number
(3) increasing atomic mass
(4) increasing atomic number
35. What is the density of N2 at STP?
(1) .00100 g/cm 3
(3) .00143 g/cm 3
(2) .00125 g/cm 3
(4) .00198 g/cm 3
36. Explain, in terms of atomic structure, why germanium is
chemically similar to silicon.

37. At STP, solid carbon can exist as graphite or as diamond.
These two forms of carbon have
(1) the same properties and the same crystal structures
(2) the same properties and different crystal structures
(3) different properties and the same crystal structures
(4) different properties and different crystal structures
38. At 298 K, oxygen (O2 ) and ozone (O3 ) have different
properties because their
(1) atoms have different atomic numbers
(2) atoms have different atomic masses
(3) molecules have different molecular structures
(4) molecules have different average kinetic energies
39. Which set of symbols represents atoms with valence
electrons in the same electron shell?
(1) Ba, Br, Bi (3) O, S, Te
(2) Sr, Sn, I (4) Mn, Hg, Cu
40. How many electrons are contained in an Au 3+ ion?
(1) 76 (3) 82
(2) 79 (4) 197
41. Which change occurs when a barium atom loses two
electrons?
(1) It becomes a negative ion and its radius decreases.
(2) It becomes a negative ion and its radius increases.
(3) It becomes a positive ion and its radius decreases.
(4) It becomes a positive ion and its radius increases.
42. Which Lewis electron-dot diagram represents a boron atom
in the ground state?
(1)
(2)
43. Which compound forms a green aqueous solution?
(1) RbCl (3) NiCl2 (2) CaCl2 (4) ZnCl2 44. Which element forms an ion that is larger than its atom?
(1) aluminum (3) magnesium
(2) chlorine (4) sodium
45. As the elements in Group 17 on the Periodic Table are
considered from top to bottom, what happens to the atomic
radius and the metallic character of each successive
element?
(1) The atomic radius and the metallic character both
increase.
(2) The atomic radius increases and the metallic character
decreases.
(3) The atomic radius decreases and the metallic character
increases.
(4) The atomic radius and the metallic character both
decrease.
46. The strength of an atom’s attraction for the electrons in a
chemical bond is the atom’s
(1) electronegativity (3) heat of reaction
(2) ionization energy (4) heat of formation
(3)
(4)
47. As the elements of Group 1 on the Periodic Table are
considered in order of increasing atomic radius, the
ionization energy of each successive element generally
(1) decreases (3) remains the same
(2) increases
48. As the elements in Period 2 of the Periodic Table are
considered in succession from left to right, there is a
decrease in atomic radius with increasing atomic number.
This may best be explained by the fact that the
(1) number of protons increases, and the number of shells
of electrons remains the same
(2) number of protons increases, and the number of shells
of electrons increases
(3) number of protons decreases, and the number of shells
of electrons remains the same
(4) number of protons decreases, and the number of shells
of electrons increases
49. Compared to the nonmetals in Period 2, the metals in
Period 2 generally have larger
(1) ionization energies (3) atomic radii
(2) electronegativities (4) atomic numbers
50. Which of these elements has the least attraction for
electrons in a chemical bond?
(1) oxygen (3) nitrogen
(2) fluorine (4) chlorine
51. Most metals have the properties of
(1) brittleness and high ionization energy
(2) brittleness and low ionization energy
(3) ductility and high ionization energy
(4) ductility and low ionization energy
52. An unknown element X can form a compound with the
formula XBr3 . In which group on the Periodic Table would
element X be found?
(1) 1 (3) 13
(2) 2 (4) 14
53. What is the chemical formula for copper(II) hydroxide?
(1) CuOH (3) Cu2 (OH)
(2) CuOH2 (4) Cu(OH) 2
54. Two different samples decompose when heated. Only one
of the samples is soluble in water. Based on this
information, these two samples are
(1) both the same element (3) both the same compound
(2) two different elements (4) two different compounds
55. The correct chemical formula for iron(II) sulfide is
(1) FeS (3) FeSO4 (2) Fe2S3 (4) Fe2 (SO4 ) 3
56. The molecular formula of glucose is C6H12O6 . What is the
empirical formula of glucose?
(1) CHO (3) C6H12O6 (2) CH2O (4) C12H24O12 57. What is the molecular formula of a compound that has a
molecular mass of 54 and the empirical formula C2H3 ?
(1) C2H3 (3) C6H9 (2) C4H6 (4) C8H12

58. The gram formula mass of NH4Cl is
(1) 22.4 g/mole (3) 53.5 g/mole
(2) 28.0 g/mole (4) 95.5 g/mole
59. The total number of moles represented by 20 grams of
CaCO3 is
(1) 1 (3) 0.1
(2) 2 (4) 0.2
60. The percentage by mass of Br in the compound AlBr3 is
closest to
(1) 10.% (3) 75%
(2) 25% (4) 90.%
61. A hydrate is a compound that includes water molecules
within its crystal structure. During an experiment to
determine the percent by mass of water in a hydrated
crystal, a student found the mass of the hydrated crystal to
be 4.10 grams. After heating to constant mass, the mass was
3.70 grams. What is the percent by mass of water in this
crystal?
(1) 90.% (3) 9.8%
(2) 11% (4) 0.40%
62. Which equation shows a conservation of mass?
(1) Na + Cl2 NaCl (3) H2O H2 + O2 (2) Al + Br2 AlBr3 (4) PCl5 PCl3 + Cl2 63. All chemical reactions have a conservation of
(1) mass, only (3) charge and energy, only
(2) mass and charge, only (4) mass, charge, and energy
64. Given the reaction:
Mg(s) + 2 AgNO 3 (aq) Mg(NO 3 ) 2 (aq) + 2 Ag(s)
Which type of reaction is represented?
(1) single replacement (3) synthesis
(2) double replacement (4) decomposition
65. Given the unbalanced equation:
__Al + __CuSO 4 __Al 2 (SO 4 ) 3 + __Cu
When the equation is balanced using the smallest
whole-number coefficients, what is the coefficient of Al?
(1) 1 (3) 3
(2) 2 (4) 4
66. Given the reaction:
PbCl 2 (aq) + Na 2 CrO 4 (aq)
PbCrO 4 (s) + 2 NaCl(aq)
What is the total number of moles of NaCl formed when 2
moles of Na2CrO4 react completely?
(1) 1 mole (3) 3 moles
(2) 2 moles (4) 4 moles
67. Which equation represents a double replacement reaction?
(1) 2 Na + 2 H2O 2 NaOH + H2 (2) CaCO3 CaO + CO2 (3) LiOH + HCl LiCl + H2O (4) CH4 + 2 O2 CO2 + 2 H2O 68. A sample is prepared by completely dissolving 10.0 grams
of NaCl in 1.0 liter of H2O. Which classification best
describes this sample?
(1) homogeneous compound
(2) homogeneous mixture
(3) heterogeneous compound
(4) heterogeneous mixture
69. Which symbol represents a particle that has the same total
number of electrons as S 2– ?
(1) O 2–
(3) Se 2–
(2) Si (4) Ar
70. What occurs when an atom of chlorine and an atom of
hydrogen become a molecule of hydrogen chloride?
(1) A chemical bond is broken and energy is released.
(2) A chemical bond is broken and energy is absorbed.
(3) A chemical bond is formed and energy is released.
(4) A chemical bond is formed and energy is absorbed.
71. Based on your Reference Tables, the atoms of which of
these elements have the strongest attraction for electrons in
a chemical bond?
(1) N (3) P
(2) Na (4) Pt
72. A substance that does not conduct electricity as a solid but
does conduct electricity when melted is most likely
classified as
(1) an ionic compound (3) a metal
(2) a molecular compound (4) a nonmetal
73. What is the total number of electrons shared in a double
covalent bond between two atoms?
(1) 1 (3) 8
(2) 2 (4) 4
74. Which statement correctly describes diamond and graphite,
which are different forms of solid carbon?
(1) They differ in their molecular structure,only.
(2) They differ in their properties, only.
(3) They differ in their molecular structure and properties.
(4) They do not differ in their molecular structure or
properties.
75. Which of these formulas contains the most polar bond?
(1) H–Br (3) H–F
(2) H–Cl (4) H–I
76. Conductivity in a metal results from the metal atoms having
(1) high electronegativity
(2) high ionization energy
(3) highly mobile protons in the nucleus
(4) highly mobile electrons in the valence shell
77. Which type of molecule is CF4 ?
(1) polar, with a symmetrical distribution of charge
(2) polar, with an asymmetrical distribution of charge
(3) nonpolar, with a symmetrical distribution of charge
(4) nonpolar, with an asymmetrical distribution of charge
78. Which formula represents a nonpolar molecule?
(1) H 2 S (3) CH 4
(2) HC1 (4) NH 3

79. Which molecule contains a nonpolar covalent bond?
(1)
(2)
80. Molecules in a sample of NH3 (…) are held closely together
by intermolecular forces
(1) existing between ions
(2) existing between electrons
(3) caused by different numbers of neutrons
(4) caused by unequal charge distribution
81. Which phase change results in the release of energy?
(1) H2O(s) H2O(…) (3) H2O(…) H2O(g) (2) H2O(s) H2O(g) (4) H2O(g) H2O(…) 82. Two samples of gold that have different temperatures are
placed in contact with one another. Heat will flow
spontaneously from a sample of gold at 60°C to a sample of
gold that has a temperature of
(1) 50°C (3) 70°C
(2) 60°C (4) 80°C
83. The average kinetic energy of water molecules is greatest in
which of these samples?
(1) 10 g of water at 35°C (3) 100 g of water at 25°C
(2) 10 g of water at 55°C (4) 100 g of water at 45°C
84. What is the equivalent of 0 Kelvin on the Celsius scale?
(1) –100º (3) –273º
(2) 100º (4) 273º
85. The temperature of a sample of water changes from 10.°C
to 20.°C when the water absorbs 420 Joules of heat. What
is the mass of the sample?
(1) 1.0 g (3) 100 g
(2) 10. g (4) 1000 g
86. What is the total number of joules released when a 5.00gram
sample of water changes from liquid to solid at 0°C?
(1) 334 J (3) 2260 J
(2) 1670 J (4) 11 300 J
87. How much energy is required to vaporize 10.00 grams of
water at its boiling point?
(1) 2.26 kJ (3) 4.2 kJ
(2) 3.34 kJ (4) 22.6 kJ
88. Which substance will sublime at 298 K?
(1) CO2 (s) (3) Si(s)
(2) Al(s) (4) KOH(s)
89. An aqueous solution of sodium chloride is best classified as
a
(1) homogeneous compound
(2) homogeneous mixture
(3) heterogeneous compound
(4) heterogeneous mixture
(3)
(4)
90. The graph below represents the uniform heating of a
substance, starting below its melting point, when the
substance is solid.
Which line segments represent an increase in average
kinetic energy?
(1) AB and BC (3) BC and DE
(2) AB and CD (4) DE and EF
91. Water has a higher melting point than hydrogen fluoride.
What is the main reason for this?
(1) Water forms more extensive hydrogen bonds than
hydrogen fluoride.
(2) The covalent bond between O and H is stronger than
that between F and H.
(3) Water contains more ions than hydrogen fluoride.
(4) Water is more polar than hydrogen fluoride.
92. When a mixture of water, sand, and salt is filtered, what
passes through the filter paper?
(1) water, only (3) water and salt, only
(2) water and sand, only (4) water, sand, and salt
93. The table below shows the normal boiling point of four
compounds.
Which compound has the strongest intermolecular forces?
(1) HF(…) (3) CH3F(…) (2) CH3Cl(…) (4) HCl(…)
94. Given the balanced equation:
4Al(s) + 3O 2 (g) 2Al 2 O 3 (s)
What is the total number of moles of O 2 (g) that must react
completely with 8.0 moles of Al(s) in order to form Al
2 O 3 (s)?

95. In the early 1900s, experiments were conducted to
determine the structure of the atom. One of these
experiments involved bombarding gold foil with alpha
particles. Most alpha particles passed directly through the
foil. Some, however, were deflected at various angles.
Based on this alpha particle experiment, state two
conclusions that were made concerning the structure of an
atom.

1. 2
2. 1
3. 4
4. 2
28. Resposes include, but are not
limited to:
•(12.00)(0.9893) +
(13.00)(0.0107)
•((12.00)(98.93) +
(13.00)(1.07))/100
29. 2
5. 4
30. 2
6. 1
31. 3
7. 3
32. 2
8. 2
33. 3
9. 1
34. 4
10. 2
35. 2
11. 2
36. 4 valence electrons
12. 4
37. 4
13. 1
38. 3
14. 1
39. 2
15. 3
40. 1
16. 3
41. 3
17. 4
42. 2
18. 4
43. 3
19. 1
44. 2
20. 3
45. 1
21. 2
46. 1
22. 1
47. 1
23. 1
48. 1
24. 3
49. 3
25. 1
50. 3
26. 1
51. 4
27. Responses include, but are not
limited to: Carbon-12 has six 52. 3
neutrons and carbon-13 has
seven neutrons • Carbon-13 53. 4
has one more neutron than
carbon-12 • C-12 has 6n, C-13 54. 4
has 7n.
55. 1
Answer Key
Midterm Review [Jan 30, 2008]
56. 2
57. 2
58. 3
59. 4
60. 4
61. 3
62. 4
63. 4
64. 1
65. 2
66. 4
67. 3
68. 2
69. 4
70. 3
71. 1
72. 1
73. 4
74. 3
75. 3
76. 4
77. 3
78. 3
79. 3
80. 4
81. 4
82. 1
83. 2
84. 3
85. 2
86. 2
87. 4
88. 1
89. 2
90. 2
91. 1
92. 3
93. 1
94. 6
95. The nucleus is small. The
nucleus is positively charged.
The atom is mostly empty space.
The nucleus is dense.

Exam Question Summary Midterm Review Jan 30, 2008
Displaying STANDARDS QUESTION ID
# QID# Ans Diff. Thinking Skills Goals
1 5651 B 2 I.1.A.
2 5485 A 1 I.1.B.
3 5681 D 2 II.3.B.
4 5650 B 1 I.1.A.
5 5568 D 1 I.2.
6 5682 A 2 I.5.B.
7 5314 C 2 I.2.
8 5513 B 1 I.3.
9 4136 A 1 I.3.
10 5231 B 1 I.4.A.
11 2740 D 1 I.4.A.
12 4370 B 2 I.4.A.
13 5569 A 2 I.4.B.
14 4940 A 1 V.6.B.i.
15 2626 C 2 I.4.C.
16 5428 D 2 II.3.B.
17 5652 C 1 I.4.C.
18 5311 D 1 XI.1.A.
19 5313 A 2 I.6.A.
20 5003 C 1 I.5.C.
21 5395 B 2 I.6.A.
22 5324 A 2 V.6.B.ii.
23 5573 A 1 II.2.A.
24 5683 C 1 II.2.B.
25 4863 A 2 II.2.B.
26 5168 A 2 II.2.C.
27 5549 FR 2 I.7.
28 5548 FR 3 I.7.
29 5315 B 1 II.2.D.
30 5161 B 1 II.2.E.
31 5523 C 2 II.2.E.
32 5657 B 2 II.1.
33 5571 C 2 II.1.
34 5570 D 1 II.1.
35 4322 B 2 II.2.G.
36 5619 FR 2 I.7.
37 5574 B 2 II.2.F.
38 5400 D 2 II.2.F.
39 5426 C 2 II.3.B.
40 5344 B 2 II.3.D.
41 5321 A 2 II.3.D.
42 5496 C 2 II.3.A.
43 4385 B 1 II.3.C.
44 4436 C 2 II.4.B.
45 5515 B 2 II.4.A.
46 5011 A 1 II.4.C.
47 5360 A 2 II.4.D.
48 5192 A 2 II.4.A.
49 4964 A 2 II.4.A.
50 5323 C 2 II.4.C.
51 4768 C 2 II.4.E.
52 5514 D 2 II.5.B.
53 5490 C 2 II.5.B.
54 5654 D 2 II.5.A.
55 5658 D 2 II.5.C.
56 5603 A 2 III.1.A.
57 5196 B 2 III.1.B.

Exam Question Summary Midterm Review Jan 30, 2008
# QID# Ans Diff. Thinking Skills Goals
58 4899 B 2 III.2.A.i.
59 2980 C 2 III.2.B.
60 5680 D 2 III.3.C.
61 5023 D 3 III.3.C.
62 5517 C 2 III.5.A.
63 5402 D 2 III.5.A.
64 5267 D 2 III.4.
65 4980 A 2 III.5.B.
66 5095 B 2 III.5.D.
67 5195 D 1 III.4.
68 5497 C 1 V.6.A.
69 5600 B 2 IV.1.B.
70 5238 D 1 IV.1.A.
71 5578 C 2 IV.1.C.
72 5519 A 2 IV.2.A.ii.
73 5662 A 2 IV.2.B.i.
74 5489 D 2 IV.2.B.ii.
75 5088 C 1 IV.3.A.
76 5322 C 2 IV.2.C.
77 5320 C 2 IV.3.A.
78 5663 C 2 IV.3.B.
79 5606 D 2 IV.3.A.
80 5410 C 2 IV.3.B.
81 5018 D 1 V.2.A.
82 5665 D 2 V.2.B.i.
83 5325 A 1 V.2.B.i.
84 3015 B 1 V.2.B.ii.
85 4515 C 3 V.4.C.
86 5693 B 2 V.4.D.
87 4324 B 2 V.4.E.
88 3227 D 1 V.4.F.
89 5661 B 1 V.6.A.
90 5437 A 2 V.4.A.
91 4727 B 2 V.5.A.
92 5022 A 2 V.6.B.i.
93 4966 C 2 V.5.C.
94 5620 FR 2 III.7.
95 5631 FR 2 I.7.