Chapter 2 Atoms Molecules and Ions
Student: ___________________________________________________________________________
NOTE: A periodic table is required to work many of the problems in this chapter.
4.
An anion is defined as
A.
B.
C.
D.
9.
a charged atom or group of atoms with a net negative charge.
a stable atom.
a group of stable atoms.
an atom or group of atoms with a net positive charge.
What percentage of the mass of a carbon-12 atom is contributed by its electrons? Given the mass of an
electron is (1/1836) amu.
A.
B.
C.
D.
E.
0.027%
6.0%
33.0%
50.0%
99.97%
10. Atoms of the same element with different mass numbers are called
A.
B.
C.
D.
E.
ions.
neutrons.
allotropes.
chemical families.
isotopes.
11. How many neutrons are there in an atom of lead whose mass number is 208?
A.
B.
C.
D.
E.
82
126
208
290
none of them
12. An atom of the isotope sulfur-31 consists of how many protons, neutrons, and electrons?
(p = proton, n = neutron, e = electron)
A.
B.
C.
D.
E.
15 p, 16 n, 15 e
16 p, 15 n, 16 e
16 p, 31 n, 16 e
32 p, 31 n, 32 e
16 p, 16 n, 15 e
13. Give the number of protons (p), electrons (e), and neutrons (n) in one atom of chlorine-37.
A.
B.
C.
D.
E.
37 p, 37 e, 17 n
17 p, 17 e, 37 n
17 p, 17 e, 20 n
37 p, 17 e, 20 n
17 p, 37 e, 17 n
14. Which one of these species is an ion?
A.
B.
C.
D.
E.
B3+
NaCl
He
14
C
none of these
15. Two isotopes of an element differ only in their
A.
B.
C.
D.
E.
symbol.
atomic number.
atomic mass.
number of protons.
number of electrons.
16. A magnesium ion, Mg2+, has
A.
B.
C.
D.
E.
12 protons and 13 electrons.
24 protons and 26 electrons.
12 protons and 10 electrons.
24 protons and 22 electrons.
12 protons and 14 electrons.
17. An aluminum ion, Al3+, has:
A.
B.
C.
D.
E.
13 protons and 13 electrons
27 protons and 24 electrons
16 protons and 13 electrons
13 protons and 10 electrons
10 protons and 13 electrons
18. An oxide ion, O2-, has:
A.
B.
C.
D.
E.
8 protons and 10 electrons
10 protons and 8 electrons
8 protons and 9 electrons
8 protons and 7 electrons
10 protons and 7 electrons
19. A sulfide ion, S2- , has:
A.
B.
C.
D.
E.
16 protons and 16 electrons
32 protons and 16 electrons
16 protons and 14 electrons
16 protons and 18 electrons
32 protons and 18 electrons
20. How many protons and electrons are present in one Br- ion?
A.
B.
C.
D.
E.
35 p, 35 e
80 p, 81 e
35 p, 34 e
35 p, 36 e
80 p, 34 e
45. The mineral pyrolusite is a compound of manganese-55 and oxygen-16. If 63% of the mass of pyrolusite is
due to manganese, what is the empirical formula of pyrolusite?
A.
B.
C.
D.
E.
MnO
Mn2O
Mn2O2
MnO2
none of these
46. The mineral manganosite is a compound of manganese-55 and oxygen-16. If 77% of the mass of
manganosite is due to manganese, what is the empirical formula of manganosite?
A.
B.
C.
D.
E.
MnO
Mn2O
Mn2O2
MnO2
none of these
47. The mineral hausmannite is a compound of manganese-55 and oxygen-16. If 72% of the mass of
hausmannite is due to manganese, what is the empirical formula of hausmannite?
A.
B.
C.
D.
E.
MnO
Mn3O
Mn3O4
Mn4O3
MnO3
48. The total number of electrons present in a sulfate ion is
A.
B.
C.
D.
E.
2.
26.
32.
48.
50.
49. The total number of electrons present in a molecule of vanadium(III) chloride is
A.
B.
C.
D.
E.
40.
57.
74.
86.
157.
50. The most abundant isotope of uranium is 238U, while all naturally occurring fluorine is 19F. A molecule of
UF6 formed from these isotopes contains
A.
B.
C.
D.
E.
146 neutrons.
152 neutrons.
200 neutrons.
206 neutrons.
352 neutrons.
51. A commonly occurring isotope of tin is tin-118, while most oxygen occurs in nature as oxygen-16. A
molecule of tin(IV) oxide formed from these isotopes contains
A.
B.
C.
D.
E.
66 neutrons.
84 neutrons.
76 neutrons.
58 neutrons.
150 neutrons.
52. Zircon is a mineral with the empirical formula ZrSiO4. If all the zirconium is 90Zr, all the silicon is 28Si,
and all the oxygen is 16O, what mass of oxygen is present in 10. g of zircon?
A.
B.
C.
D.
E.
0.88 g
1.2 g
1.8 g
3.5 g
5.4 g
53. The mineral orpiment, having the empirical formula As2S3, was used in ancient times as a cosmetic. What
mass of arsenic is present in 5.0 g of orpiment?
[Given: naturally occurring arsenic is all arsenic-75; assume that all naturally occurring sulfur is sulfur-32
(only approximately true)]
A.
B.
C.
D.
E.
0.61 g
3.0 g
1.5 g
2.0 g
3.5 g
96. The table below describes four atoms.
Which atoms represent the same element?
97. Consider a neutral atom of the element phosphorus.
How many electrons does the atom contain?
98. Consider a neutral atom of the element phosphorus.
How many protons does the atom contain?
99. Consider a neutral atom of the element phosphorus.
How many neutrons does the atom contain?
100. Consider a neutral atom of the element potassium.
How many electrons does it contain?
101. Consider a neutral atom of the element potassium.
How many protons does it contain?
102. Consider a neutral atom of the element potassium.
How many neutrons does it contain?
103. Consider a neutral bromine atom.
How many electrons does it contain?
104. Consider a neutral bromine atom.
How many protons does it contain?
105. Consider a neutral bromine atom.
How many neutrons does it contain?
106. Consider a neutral atom of the element aluminum.
How many electrons does it contain?
107. Consider a neutral atom of the element aluminum.
How many protons does it contain?
108. Consider a neutral atom of the element aluminum.
How many neutrons does it contain?
133. Almost all the mass of an atom is concentrated in the nucleus.
True False
137. The proton is about 1840 times heavier than the electron.
True False
138. The atomic number is equal to the number of protons in the nucleus of each atom of an element.
True False
139. The number of neutrons in all atoms of an element is the same.
True False
140. An empirical formula tells us which elements are present in a compound and gives us the simplest, wholenumber ratio of the atoms of these elements in the compound.
True False
Chapter 2 Atoms Molecules and Ions Key
1.D
2.C
3.E
4.A
5.B
6.B
7.E
8.A
9.A
10.E
11.B
12.B
13.C
14.A
15.C
16.C
17.D
18.A
19.D
20.D
21.D
22.C
23.B
24.A
25.C
26.D
27.B
28.E
29.D
30.B
31.B
32.D
33.D
34.A
35.E
36.E
37.C
38.A
39.D
40.D
41.D
42.B
43.E
44.A
45.D
46.A
47.C
48.E
49.C
50.D
51.B
52.D
53.B
54.B
55.A
56.E
57.(Note that answers will vary.) Marie Curie discovered two new elements, and is one of three people to win two Nobel Prizes. She also suggested
the term "radioactivity" to describe the spontaneous emission of particles and/or radiation.
58.Matter can be neither created nor destroyed.
59.electrons, protons, and neutrons
60.alpha, beta, and gamma radiation
61.26 electrons
62.26 protons
63.29 neutrons
64.A molecule is an aggregate of at least two atoms in a definite arrangement held together by chemical forces.
65.Hydrogen, nitrogen, oxygen, fluorine, chlorine, bromine, iodine
66.An ion is an atom or group of atoms that has a net positive or negative charge E.
67.(Answers will vary.) Atoms are mostly empty space. The mass is concentrated mostly at the center of the atom.
68.Group 1A
69.Group 2A
70.Group 7A
71.Group 8A
72.28
73.12
74.54
75.92
76.10
77.4
78.60
79.27
80.3
81.24
82.K2O
83.CaCl2
84.CS2
85.LiOH
86.NiSO4
87.Iron(II) sulfide
88.Sodium hydride
89.Copper(I) chloride
90.Silver chloride
91.Iron(III) oxide (or ferric oxide)
92.Copper(II) carbonate
93.Iron(II) sulfate
94.Sodium phosphate
95.Aluminum nitrate
96. Atoms A and D represent the same element, Atoms B and C represent the same element.
97. 15
98. 15
99. 16
100. 19
101. 19
102. 21
103. 35
104. 35
105. 46
106. 13
107. 13
108. 14
109.(Answers will vary.) iron, Fe; sodium, Na; chlorine, Cl; nitrogen, N
110.Mg(NO3)2
111.Ca3(PO4)2
112.Fe3(PO4)2
113.CuBr2
114.(NH4)2SO4
115.HCl
116.H2CO3
117.HNO3
118.H2SO4
119.HF
120.Iodine, chlorine
121.10
122.32
123. 26
124. 10
125.An allotrope is one of the two or more distinct forms of an element.
126.Atoms of the same element that have the same atomic number but different mass numbers.
127.Sodium nitrite
128.Potassium chloride
129.Magnesium nitrate
130.(NH4)3PO4
131.PbCl2
132.CaCO3
133.TRUE
134.TRUE
135.FALSE
136.FALSE
137.TRUE
138.TRUE
139.FALSE
140.TRUE
5. The diameter of a neutral helium atom is about 1 × 102 pm. Suppose that we could line
up helium atoms side by side in contact with one another. Approximately how many
atoms would it take to make the distance from end to end 1 cm?
A) 1 × 108 He atoms
B) 2 × 105 He atoms
C) 1 × 109 He atoms
D) 5 × 106 He atoms
6. Roughly speaking, the radius of an atom is about 10,000 times greater than that of its
nucleus. If an atom were magnified so that the radius of its nucleus became 2.0 cm,
about the size of a marble, what would be the radius of the atom in miles? (1 mi = 1609
m.)
A) 0.24 mi
B) 12 mi
C) 3.3 mi
D) 0.12 mi
7. Why does knowledge of atomic number enable us to deduce the number of electrons
present in an atom?
A) The number of electrons present in an atom is equal to twice the atomic number.
B) The number of electrons present in an atom is equal to the atomic weight minus the
atomic number.
C) The number of electrons present in a neutral atom is equal to the atomic number.
D) The number of electrons present in an atom is equal to the number of neutrons
present.
8. Why do all atoms of an element have the same atomic number, although they may have
different mass numbers?
A) All atoms of an element have the same number of neutrons, but may have different
numbers of protons.
B) All atoms of an element have the same number of protons, but may have different
numbers of neutrons.
C) The sum of neutrons and protons is the same for every atom of an element.
D) The sum of neutrons and electrons is the same for every atom of an element.
9. What do we call atoms of the same elements with different mass numbers?
A)  particles
B) isomers
C) isotopes
D) nuclei
10. What is the mass number of an iron atom that has 28 neutrons?
A) 54
B) 28
C) 56
D) 26
11. Calculate the number of neutrons of 239Pu.
A) 94
B) 145
C) 120
D) 239
12.
13.
What is the number of protons and the number of neutrons in the nucleus of
A) 25 protons, 12 neutrons
B) 13 protons, 12 neutrons
C) 12 protons, 25 neutrons
D) 12 protons, 13 neutrons
What is the number of protons, neutrons, and electrons in
A) 29 protons, 34 neutrons, 34 electrons
B) 29 protons, 34 neutrons, 29 electrons
C) 34 protons, 29 neutrons, 34 electrons
D) 29 protons, 63 neutrons, 29 electrons
63
29
Cu
14. What is the appropriate symbol for the isotope Z = 11, A = 23?
A) 34
23 V
B)
23
12
Mg
C)
23
11
Na
D)
23
11
V
15. What is the appropriate symbol for the isotope Z = 28, A = 64?
28
A) 64
Ni
B)
64
28
Kr
C)
64
28
Gd
D)
64
28
Ni
?
25
12
Mg
?
16. What is the appropriate symbol for the isotope Z = 74, A = 186?
A) 186
74 W
B)
186
74
C)
186
112
Sg
W
D) the element does not exist
17. What is the appropriate symbol for the isotope Z = 80, A = 201?
201
A) 121
Hg
B)
201
80
C)
80
21
Hg
Sc
D) the element does not exist
18. Which of the following is a difference between metals and nonmetals?
A) Metals contain electrons, nonmetals do not.
B) Metals are good conductors of electricity; nonmetals are not.
C) Nonmetals are all gases while metals are all solids.
D) none of the above
19. Sodium (Na) and cesium (Cs) are members of which of the following categories?
A) alkali metals
B) alkaline earth metals
C) halogens
D) noble gases
20. Helium (He) and radon (Rn) are members of which of the following categories?
A) alkali metals
B) alkaline earth metals
C) halogens
D) noble gases
21. Elements whose names end with ium are usually metals; sodium is one example.
Identify a nonmetal whose name also ends with ium.
A) potassium
B) magnesium
C) helium
D) barium
22. The elements near the bottom of the periodic table are more likely to be members of
what category?
A) metals
B) nonmetals
C) halogens
D) noble gases
23. Group the following elements in pairs that you would expect to show similar chemical
properties: K, F, P, Na, Cl, and N.
A) K/N; F/Na; Cl/N
B) K/Na; F/Cl; P/N
C) K/F; P/Na; Cl/N
D) K/P; F/Na; Cl/N
24. What is the difference between an atom and a molecule?
A) A molecule has more electrons than an atom.
B) An atom is charged while a molecule is not.
C) A molecule is an aggregate of atoms, while an atom, by definition, is a single
particle.
D) A molecule is bigger than an atom.
25. How are allotropes different from isotopes?
A) Allotropes are ionic, while isotopes are not.
B) Allotropes are gases, while isotopes are generally solids.
C) Allotropes are single atoms, while isotopes are aggregates of atoms.
D) Allotropes are different molecular combinations of a single element; isotopes are
atoms of the same element with different masses.
26. NH4+ is an example of which of the following?
A) a monatomic cation
B) a monatomic anion
C) a polyatomic cation
D) a polyatomic anion
27. Which of the following is an element?
A) N2
B) NH3
C) NO
D) CO
28. Which of the following is a compound?
A) N2
B) H2
C) O3
D) SO2
29. Which of the following describes the molecule SO2?
A) A diatomic molecule containing atoms of the same element.
B) A diatomic molecule containing atoms of different elements.
C) A polyatomic molecule containing atoms of the same element.
D) A polyatomic molecule containing atoms of different elements.
30. Which of the following describes the molecule CO?
A) A diatomic molecule containing atoms of the same element.
B) A diatomic molecule containing atoms of different elements.
C) A polyatomic molecule containing atoms of the same element.
D) A polyatomic molecule containing atoms of different elements.
31. What is the number of protons and electrons in Na+?
A) 11 protons, 10 electrons
B) 11 protons, 11 electrons
C) 10 protons, 11 electrons
D) 11 protons, 12 electrons
32. What is the number of protons and electrons in S2–?
A) 16 protons, 16 electrons
B) 16 protons, 17 electrons
C) 16 protons, 14 electrons
D) 16 protons, 18 electrons
33. What is the number of protons and electrons in Mg2+?
A) 12 protons, 12 electrons
B) 12 protons, 14 electrons
C) 12 protons, 10 electrons
D) 14 protons, 12 electrons
34. What is the number of protons and electrons in Br–?
A) 35 protons, 35 electrons
B) 35 protons, 36 electrons
C) 35 protons, 37 electrons
D) 34 protons, 35 electrons
35. Which of the following molecules contains two elements in a ratio of 2:1?
A) NO
B) NCl3
C) N2O4
D) P4O6
36. Which compound has the same empirical formula as C6H12O6?
A) C12H24O12
B) C3H3O3
C) CH2ON
D) CHO2
37. Which pair of compounds has the same empirical formula?
A) C2H6O3 and CH2O
B) NO2 and N2O4
C) C6H6and CH4
D) NO2 and NO4
38. What is the empirical formula of C6H6?
A) C6O
B) CH6
C) C3H3
D) CH
39. What is the empirical formula of P4O10?
A) P4O5
B) P2O5
C) PO
D) PO5
40. What is the empirical formula of N2O5?
A) N2O5
B) NO
C) NO5
D) N2O
41. What is the empirical formula of Na2S2O4?
A) Na2SO2
B) NaSO
C) Na2S2O2
D) NaSO2
42. What is the molecular formula of glycine, an amino acid present in proteins? The color
codes are: black (carbon), blue (nitrogen), red (oxygen), and gray (hydrogen).
A)
B)
C)
D)
C2HN5O2
CH5NO2
C2H5NO2
C2H5O2
43. What is the molecular formula of ethanol? The color codes are: black (carbon), red
(oxygen), and gray (hydrogen).
A)
B)
C)
D)
C2H6O
CH6O2
C6H6O
C2H2O
44. Which of the following compounds is likely to be molecular?
A) PbCl2
B) LiF
C) B2H6
D) KCl
45. Which of the following compounds is likely to be ionic?
A) CH4
B) NaBr
C) CCl4
D) NF3
46. Which of the following compounds is named potassium hydrogen phosphate?
A) KH2PO4
B) K2HPO4
C) K3PO4
D) K2Cr2O7
47. Which of the following compounds is named lithium carbonate?
A) Na2CO3
B) LiHCO3
C) LiCO
D) Li2CO3
48. What is the name of KMnO4?
A) manganese potash
B) potassium managnese tetroxide
C) potassium permanganate
D) potassium oxide
49. What is the name of KClO?
A) potassium chlorite
B) potassium chloride
C) potassium hypochlorite
D) potassium oxide
50. What is the formula for ammonium sulfate?
A) NH4SO4
B) NH4(SO4)2
C) (NH4)2SO4
D) NH4S
51. What is the formula for calcium hydrogen phosphate?
A) Ca2HPO4
B) Ca(HPO4)2
C) Ca2H2PO4
D) CaHPO4
52. What is the formula for lead (II) carbonate?
A) PbCO3
B) Pb2CO3
C) Pb(CO3)2
D) PbC
53. What is the formula for copper (II) cyanide?
A) CuCN
B) Cu(CN)2
C) Cu2CN
D) CuNCO
54. A sample of a uranium compound is found to be losing mass gradually. What is
happening to the sample?
A) the uranium is decaying radioactively
B) the compound is subliming
C) changes in humidity are altering the mass of the sample
D) the compound is reacting with oxygen in the air
55. In which one of the following pairs do the two species resemble each other most closely
in chemical properties?
1

A) 11 H
and 1 H
B)
14
7
N
and
14
7
N 3
C and 13
6 C
23
23
D) 11
Na 
Na
and 11
C)
12
6
56. One isotope of a metallic element has mass number 65 and 35 neutrons in the nucleus.
The cation derived from the isotope has 28 electrons. What is the symbol for this cation?
A) Br–
B) Br2+
C) Tb2+
D) Zn2+
57. One isotope of a nonmetallic element has mass number 127 and 74 neutrons in the
nucleus. The anion derived from the isotope has 54 electrons. What is the symbol for
this anion?
A) I–
B) W–
C) Xe+
D) the element does not exist
Use the following to answer questions 58-61:
ATOM OR
ION OF ELEMENT
Number of electrons
Number of protons
Number of neutrons
A
5
5
5
B
10
7
7
C
18
19
20
D
28
30
36
58. Which of the species are neutral?
A) C
B) A and B
C) A, F and G
D) E
E
36
35
46
F
5
5
6
G
9
9
10
59. Which of the species are negatively charged?
A) C and D
B) D, E and G
C) A and D
D) B and E
60. Which of the species are positively charged?
A) C and D
B) B and E
C) A, C and F
D) G
61. What are the conventional symbols for species C and F?
 11
A) 39
20 Ca , 6 C
39
B) 19
K  11
,5B
39
20
Ca 
11
,5B
39
D) 19
K  11
, 6C
C)
62. What is wrong with or ambiguous about the phrase “four molecules of NaCl”?
A) Four molecules of NaCl would require the formula to be Na4Cl4
B) NaCl molecules do not exist in aggregates of four
C) The formula for NaCl is incorrect
D) NaCl is ionic and does not exist in the form of molecules
63. Which of the following are elements? (a) SO2, (b) S8, (c) Cs, (d) N2O5, (e) O, (f) O2, (g)
O3, (h) CH4, (i) KBr, (j) S, (k) P4, (l) LiF
A) (b), (c), (e) and (j) only
B) (d) and (l)
C) (f), (g) and (k) only
D) (b), (c), (e), (f), (g), (j), and (k)
64. Which of the following are compounds but not molecules? (a) SO2, (b) S8, (c) Cs, (d)
N2O5, (e) O, (f) O2, (g) O3, (h) CH4, (i) KBr, (j) S, (k) P4, (l) LiF
A) (f) and (h)
B) (a) and (d)
C) (i) and (l)
D) (d)
65. Why is magnesium chloride (MgCl2) not called magnesium(II) chloride?
A) The magnesium in MgCl2 does not have a charge of 2+.
B) Magnesium (II) is the only common ion of magnesium.
C) Magnesium chloride is not ionic.
D) Only iron and copper use the Roman numeral convention.
66. Some compounds are better known by their common names than by their systematic
chemical names. What is the chemical formula of baking soda?
A) NaHCO3
B) Na2CO3
C) Ca(HCO3)2
D) CaCO3
67. What is the chemical formula of slaked lime?
A) NaOH
B) Na(OH)2
C) CaOH
D) Ca(OH)2
68. Which elements are most likely to form ionic compounds?
A) halogens and noble gases
B) transition metals and metalloids
C) metals and halogens
D) metals and noble gases
69. Which metallic elements are most likely to form cations with different charges?
A) alkali metals
B) transition metals
C) alkaline earth metals
D) metalloids
70. Which of the following elements has a common ion with a 2+ charge?
A) Li
B) Mg
C) S
D) I
71. Which of the following elements has a common ion with a 2– charge?
A) Li
B) Mg
C) S
D) I
72. Which of the following symbols provides the most information about the atom?
A) 23Na
B) 11Na
C) Na
D) all symbols provide the same information
73. Which of the following acids contains a Group 7A element?
A) HNO2
B) H2SO4
C) HBr
D) H3PO4
74. Which of the following acids contains a Group 5A element?
A) HClO4
B) H2SO4
C) HBr
D) H3PO4
75. Of the 113 elements known, which two are liquids at room temperature (25 °C)? What
are they?
A) Hg and Br
B) H and B
C) Xe and N
D) P and S
76. Which of the following elements exist as gases at room temperature?
A) P and S
B) H and N
C) Br and C
D) I and B
77. The elements in Group 8A of the periodic table are called noble gases. Can you suggest
what “noble” means in this context?
A) the noble gases were so named to honor Alfred Nobel
B) the noble gases were discovered by a member of a royal family
C) the noble gases were once used to make perfume for the wealthy of Europe
D) the noble gases do not associate with other atoms
78. The formula for calcium oxide is CaO. What are the formulas for magnesium oxide and
strontium oxide?
A) Mg2O, Sr2O
B) MgO2, SrO2
C) MgO, SrO
D) MgO, Sr3O
79. A common mineral of barium is barytes, or barium sulfate (BaSO4). Because elements
in the same periodic group have similar chemical properties, we might expect to find
some radium sulfate (RaSO4) mixed with barytes since radium is the last member of
Group 2A. However, the only source of radium compounds in nature is in uranium
minerals. Why?
A) radium and barium repel each other
B) all radium is formed by radioactive decay of uranium
C) radium only forms compounds with uranium
D) radium is too heavy to form sulfates
80. Which of the following elements is named after a place? (Hint: See Appendix 1.)
A) sodium
B) europium
C) nobelium
D) zirconium
81. Which of the following elements is named after a person? (Hint: See Appendix 1.)
A) sodium
B) europium
C) nobelium
D) zirconium
82. Name the only country that is named after an element. (Hint: This country is in South
America.)
A) Bolivia
B) Peru
C) Uruguay
D) Argentina
83. Fluorine reacts with hydrogen (H) and deuterium (D) to form hydrogen fluoride (HF)
2
H
and deuterium fluoride (DF), where deuterium 1 is an isotope of hydrogen. If a given
amount of fluorine reacts with one gram of hydrogen, with how much deuterium would
the same amount of fluorine react?
A) two grams
B) one gram
C) one half gram
D) deuterium does not react with fluorine
84. Predict the formula of a binary compound formed from F and O.
A) F2O
B) FO
C) FO2
D) FO4
85. Predict the formula of a binary compound formed from Sr and Cl.
A) Sr2Cl
B) Sr2Cl2
C) SrCl
D) SrCl2
86. Which of the following is a halogen whose anion contains 36 electrons?
A) Se
B) Br
C) Kr
D) Rb
87. Which of the following is an alkali metal whose cation contains 36 electrons?
A) Se
B) Br
C) Kr
D) Rb
Answer Key
1.
2.
3.
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5.
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8.
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13.
14.
15.
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31.
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33.
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35.
36.
37.
38.
39.
40.
41.
42.
43.
44.
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46.
47.
48.
49.
50.
B
C
B
D
A
D
C
B
C
A
B
D
B
C
D
A
B
B
A
D
C
A
B
C
D
C
A
D
D
B
A
D
C
B
C
A
B
D
B
A
D
C
A
C
B
B
D
C
C
C
51.
52.
53.
54.
55.
56.
57.
58.
59.
60.
61.
62.
63.
64.
65.
66.
67.
68.
69.
70.
71.
72.
73.
74.
75.
76.
77.
78.
79.
80.
81.
82.
83.
84.
85.
86.
87.
D
A
B
A
C
D
A
C
D
A
B
D
D
C
B
A
D
C
B
B
C
A
C
D
A
B
D
C
B
B
C
D
A
A
D
B
D