Chapter 20: The Representative Elements
1. In a given period this group has the element with the largest atomic radius.
A)
Group 1A
B)
Group 2A
C)
Group 3A
D)
Group 4A
E)
Group 5A
2. Which of the following is a metalloid?
A)
carbon
B)
oxygen
C)
hydrogen
D)
copper
E)
silicon
3. Which of the following exhibits the greatest metallic character?
A)
Cs
B)
Rb
C)
K
D)
Na
E)
All are equally metallic.
4. What is the most abundant element found in the human body?
A)
carbon
B)
hydrogen
C)
calcium
D)
oxygen
E)
water
5. Hydrogen and lithium react very differently, although they are both members of Group 1.
What is the primary reason for this difference?
A)
The metallic character increases going down a group.
B)
The ionization energy increases going down a group.
C)
Electron affinity increases going down a group.
D)
Electronegativity increases going down a group.
E)
There is a very large difference in the atomic radii of H and Li.
6. All of the following are semimetals except
A)
At
B)
Ge
C)
Al
D)
Sb
E)
Si
7. Which oxide of a Group 2A element is amphoteric?
A)
Be
B)
Mg
C)
Ca
D)
Sr
E)
Ba
8. Which oxide of a Group 2A element is not highly ionic?
A)
Be
B)
Mg
C)
Ca
D)
Sr
E)
Ba
9. Choose the metal with the largest first ionization energy.
A)
Na
B)
Mg
C)
Al
D)
K
E)
Ca
10. Which group shows the correct order of first ionization energy?
A)
Na > P > Cl
B)
Cs > Na > K
C)
K > Ca > Ge
D)
Cs < Rb < Na
E)
Al > Si > P
11. Which element of Group 3A behaves as a nonmetal or semimetal?
A)
B
B)
Al
C)
Ga
D)
In
E)
B and Al
12. What reason is given for the stability of C–C, N–N, and O–O bonds, compared to the
instability of Si–Si, P–P, and S–S bonds?
A)
Their metallic character varies greatly.
B)
Large differences in their ionization energies.
C)
Large differences in their electronegativities.
D)
Large differences in their abilities to form strong pi bonds.
E)
None of these.
13. What are the most abundant metals in the earth’s crust, oceans, and atmosphere?
A)
titanium and silicon
B)
aluminum and iron
C)
manganese and nickel
D)
tin and lead
E)
iron and lead
14. Which of the following oxides is amphoteric?
A)
BeO
B)
MgO
C)
CaO
D)
SrO
E)
BaO
15. True or false: Hydrogen is a nonmetal while lithium is an active metal, even though they are
in the same group.
A)
True. Such differences are common for elements in the same group.
B)
False. Because the elements are in the same group, they have similar metallic
qualities.
C)
True. This can be explained because of the very large difference in atomic radii
between hydrogen and lithium.
D)
False. Both hydrogen and lithium are nonmetals
E)
None of these.
16. Choose the metal with the smallest radius.
A)
Ca
B)
Na
C)
K
D)
Mg
E)
Al
17. Within a group, as the atomic numbers of the elements increase, the
A)
ionization energies decrease
B)
atomic masses decrease
C)
elements become less metallic
D)
atomic radii decrease
E)
metallic character decreases
18. Choose the element with the largest atomic radius.
A)
Li
B)
B
C)
N
D)
O
E)
Ne
19. Choose the element with the smallest atomic radius.
A)
Li
B)
Na
C)
K
D)
Rb
E)
Cs
20. Choose the element obtained from liquification of air.
A)
N
B)
P
C)
As
D)
Sb
E)
Bi
21. Which of the following is the second most abundant (by mass) element in the earth’s crust,
oceans, and atmosphere?
A)
hydrogen
B)
oxygen
C)
carbon
D)
aluminum
E)
silicon
22. The compound SiO2 does not exist as a discrete molecule while CO2 does. This can be
explained because:
A)
The Si—O bond is unstable.
B)
The Lewis structure of SiO2 has an even number of electrons.
C)
The SiO2 is a solid while CO2 is a gas.
D)
The 3p orbital of the Si has little overlap with the 2p of the O.
E)
None of these.
23. Both CO2 and SiO2 appear to have valid Lewis structures. Using the molecular orbital
model, why then are CO2 molecules stable and SiO2 molecules not stable?
A)
CO2 is able to form sigma bonds and SiO2 is not.
B)
The silicon 3p valence orbitals do not overlap very effectively with the smaller
oxygen 2p orbitals.
C)
The carbon atom is larger than the silicon atom, giving carbon a higher electron
density and thus better pi bonding.
D)
Silicon prefers to bond to other silicon atoms over oxygen atoms.
E)
At least two of the above are correct.
24. The elements in this group are termed alkali metals.
A)
Group 1A
B)
Group 2A
C)
Group 3A
D)
Group 4A
E)
Group 5A
25. Which group contains the most active metals?
A)
Group 1A
B)
Group 3A
C)
Group 2A
D)
Group 4A
E)
Group 7A
26. Choose the element that is the strongest reducing agent.
A)
Li
B)
Na
C)
K
D)
Rb
E)
Cs
27. Choose the element with the highest melting point.
A)
Li
B)
Na
C)
K
D)
Rb
E)
Cs
28. Choose the element whose ion has the largest concentration inside a human cell.
A)
Li
B)
Na
C)
K
D)
Rb
E)
Cs
29. Choose the metal with the lowest melting point.
A)
Li
B)
Na
C)
K
D)
Rb
E)
Cs
30. What ions are very important for the proper functioning of biologic systems, such as nerves
and muscles?
A)
alkaline earth metal ions
B)
alkali metal ions
C)
oxygen ions
D)
hydrogen ions
E)
nitrogen ions
31. The strongest reducing agent in the alkali metals is:
A)
K
B)
Na
C)
Cs
D)
Fr
E)
Li
32. Which of the following is the best explanation as to why lithium is the strongest reducing
agent of the alkali metals?
A)
The ionization energy of lithium is the highest of the alkali metals.
B)
The ionization energy of lithium is the lowest of the alkali metals.
C)
The standard reduction potential of lithium is the most positive of the alkali metals.
D)
The relatively high charge density of lithium compared to the other alkali metals.
E)
None of these.
33. Because Li is the strongest reducing agent of the alkali metals, it reacts most quickly with
water of the alkali metals.
34. Ionic hydrides are formed when hydrogen combines with elements from:
I.
Group 1A
II.
Group 2A
III
Group 3A
A)
I, II, and III
B)
I and II
C)
I and III
D)
II and III
E)
none of these
35. __________ are formed when hydrogen combines with other nonmetals.
A)
Covalent hydrides
B)
Nonmetallic hydrides
C)
Active hydrides
D)
Interstitial hydrides
E)
Ionic hydrides
36. __________ are formed when transition metal crystals are treated with hydrogen gas.
A)
Covalent hydrides
B)
Metallic hydrides
C)
Active hydrides
D)
Saltlike hydrides
E)
Ionic hydrides
37. Ionic hydrides are formed with hydrogen combined with elements from
A)
group 1A
B)
group 2A
C)
group 3A
D)
all of the above
E)
two of the above
38. The major industrial source of hydrogen gas is the reaction of methane and water at high
temperatures (800 – 1000°C) and high pressures (10 – 15 atm) with nickel as a catalyst.
CH4(g) + H2O(g) CO2(g) + 3H2(g)
If 171.5 g of CH4 and 171.5 g of H2O are reacted at 945°C and 11.0 atm, how much
hydrogen should be available for industrial use?
A)
201 L
B)
291 L
C)
259 L
D)
28.8 L
E)
86.5 L
39. Which statements about hydrogen are true?
I.
H has a lower ionization energy than He.
II.
H– is smaller than H.
III.
H bonds with the halogens to form polar covalent
compounds.
IV.
H is always a metal.
V.
H does not have a second ionization energy.
A)
I, V
B)
II, IV
C)
I, III, V
D)
II, IV, V
E)
I, III, IV, V
40. Salts can consist of hydrogen.
41. Choose the metal that reacts least vigorously with water.
A)
Mg
B)
Ca
C)
Sr
D)
Ba
E)
All of these react equally vigorously with water.
42. Choose the metal that is produced by electrolysis of its molten chloride salt.
A)
Mg
B)
Ca
C)
Sr
D)
Ba
E)
all of these
43. Choose the group that matches the following description: reacts with H2 to form compounds
with the general formula MH2.
A)
Group 1A
B)
Group 2A
C)
Group 3A
D)
Group 4A
E)
Group 5A
44. Choose the group that matches the following description: reacts with F2 to form compounds
with the general formula MF2.
A)
Group 1A
B)
Group 2A
C)
Group 3A
D)
Group 4A
E)
Group 5A
45. Elements in this group lose two valence electrons to non-metals to form ionic compounds.
A)
Group 1A
B)
Group 2A
C)
Group 3A
D)
Group 4A
E)
Group 5A
46. Choose the solid that has the smallest ionization energy.
A)
Be
B)
Mg
C)
Ca
D)
Sr
E)
Ba
47. Which of the following ions interferes with the action of detergents in hard water?
A)
Na+
B)
Ca2+
C)
Mg2+
D)
Ca2+ and Mg2+
E)
Na+, Ca2+, and Mg2+
48. What element is found in the structural minerals that make up our bones and teeth?
A)
strontium
B)
barium
C)
calcium
D)
silicon
E)
magnesium
49. In cation-exchange resins, what ion replaces Ca2+ and Mg2+ in the hard water that is passed
over the resin?
A)
H+
B)
Li+
C)
Na+
D)
K+
E)
Ba2+
50. Arrange the following Group 2A elements (in their ionic form) from largest to smallest
atomic radius.
A)
Ra2+ > Ba2+ > Sr2+ > Ca2+ > Mg2+
B)
Sr2+ > Ca2+ > Ba2+ > Mg2+ > Ra2+
C)
Ba2+ > Ra2+ > Ca2+ > Sr2+ > Mg2+
D)
Mg2+ > Ca2+ > Sr2+ > Ba2+ > Ra2+
E)
Ra2+ > Mg2+ > Ba2+ > Ca2+ > Sr2+
51. Which of the following is the best explanation for how a water softener works?
A)
When hard water passes over a resin in the softener, the Ca2+ and Mg2+ ions in the
water bind to the resin in place of Na+ ions.
B)
The softener releases an acid to interact with the Ca2+ and Mg2+ ions in the hard
water to neutralize them.
C)
When hard water passes through the softener, the Ca2+ and Mg2+ ions are removed
through electrolysis.
D)
The softener releases K+ ions to counteract the Ca2+ and Mg2+ ions in the hard
water.
E)
When hard water passes through the softener, the Ca2+ and Mg2+ ions precipitate
out as Mg(OH)2 and Ca(OH)2.
52. Alkaline earth metals react less vigorously with water than do the alkali metals.
53. Which of these Group 2A elements reacts least vigorously with water?
A)
Mg
B)
Sr
C)
Ca
D)
Ba
E)
All of these react in the same manner.
54. The element with the lowest melting point is:
A)
B
B)
Al
C)
Ga
D)
Tl
E)
All have the same melting point.
55. The element with the widest liquid range is:
A)
B
B)
Al
C)
Ga
D)
Tl
E)
All are the same.
56. The ion that aluminum is most likely to form is isoelectronic with:
A)
Ar
B)
Na
C)
Ne
D)
Mg
E)
none of these
57. Which of the following metals has the highest melting point?
A)
Na
B)
Mg
C)
Al
D)
Ca
E)
K
58. An element that exhibits the oxidation states +1 and +3 is:
A)
B
B)
Al
C)
Ga
D)
In
E)
all of these
59. The Group 3A element with the highest ionization energy is:
A)
B
B)
Al
C)
Ga
D)
Tl
E)
All are the same.
60. The element found in bauxite is:
A)
B
B)
Al
C)
Ga
D)
Tl
E)
all of these
61. The element that reacts with N2 to form a compound of the general formula MN is:
A)
B
B)
Al
C)
Ga
D)
Tl
E)
all of these
62. The Group 3A elements are all metals.
63. Choose the group that matches the following description: contains two of the most
important elements found on earth.
A)
Group 1A
B)
Group 2A
C)
Group 3A
D)
Group 4A
E)
Group 5A
64. Order the following bonds from highest to lowest bond energy: carbon–carbon, silicon–
silicon, silicon–oxygen.
A)
C—C, Si—Si, S—O
B)
Si—O, C—C, Si—Si
C)
Si—Si, Si—O, C—C
D)
Si—O, Si—Si, C—C
E)
C—C, Si—O, Si—Si
65. Which group contains two elements that exhibit +2 and +4 oxidation states?
A)
Group 1A
B)
Group 3A
C)
Group 4A
D)
Group 5A
E)
Group 7A
66. What are the forms of elemental carbon?
A)
graphite and diamond
B)
graphite, diamond, and fullerenes
C)
graphite and fullerenes
D)
diamond and fullerenes
E)
diamond, graphite, and carbonite
67. The solid substance with the empirical formula SiO2 is commonly called:
A)
silicon
B)
silica
C)
silicate
D)
silicone
E)
none of these
68. How many of the following statements are false?
I.
The group 3A elements are all metals.
II
Alkaline earth metals react less vigorously with water than do the alkali
metals.
III.
Salts can consist of hydrogen.
IV.
Because Li is the strongest reducing agent of the alkali metals, it reacts
most quickly with water of the alkali metals.
A)
0
B)
1
C)
2
D)
3
E)
4
69. Which of the following is the most abundant metal on earth?
A)
calcium
B)
iron
C)
copper
D)
aluminum
E)
zinc
70. Which element is found in the ore galena?
A)
tin
B)
lead
C)
aluminum
D)
silicon
E)
germanium
71. The largest commercial use of lead is in
A)
gasoline
B)
protective coatings for steel
C)
semiconductors
D)
paints
E)
batteries used in automobiles
72. With which of the following elements does silicon form the strongest bonds?
A)
Si
B)
C
C)
H
D)
O
E)
B
73. The chemistry of silicon is dominated by its bonding with
A)
Cl
B)
S
C)
Al
D)
F
E)
none of these
74. Which element in Group 4A has the strongest metallic character?
A)
Pb
B)
C
C)
Si
D)
Ge
E)
None of these are metals.
75. Choose the element with the largest electronegativity.
A)
N
B)
P
C)
As
D)
Sb
E)
Bi
76. Choose the most metallic element.
A)
N
B)
P
C)
As
D)
Sb
E)
Bi
77. Choose the element with the largest ionization energy.
A)
N
B)
P
C)
As
D)
Sb
E)
Bi
78. Which Group 5A element cannot form molecules with five covalent bonds?