Introduction to chemistry
Multiple Choice
1. Which SI prefix means 1000?
A. Milli
B. Centi
C. Deci
D. Kilo
Answer: D; Difficulty: easy; Reference: Section 2.5
2. The number, 14.74999, when rounded to three digits is
A. 15.0
B. 14.8
C. 14.7
D. 10.0
Answer: C; Difficulty: easy; Reference: Section 2.3
3. How many significant figures are in the number 14.38?
A. 1
B. 2
C. 3
D. 4
Answer: D; Difficulty: easy; Reference: Section 2.3
4. How many significant figures are in the number 1.500?
A. 1
B. 2
C. 3
D. 4
Answer: D; Difficulty: easy; Reference: Section 2.3
5. How many significant figures are in the number 14.04?
A. 1
B. 2
C. 3
D. 4
Answer: D; Difficulty: easy; Reference: Section 2.3
6. How many significant figures are in the number 1360?
A. 1
B. 2
C. 3
D. 4
Answer: C; Difficulty: easy; Reference: Section 2.3
7. How many significant figures are in the number 0.005?
A. 1
B. 2
C. 3
D. 4
Answer: A; Difficulty: easy; Reference: Section 2.3
8. How many significant digits are in the number 1.30 X 104?
A. 1
B. 2
C. 3
D. 4
Answer: C; Difficulty: easy; Reference: Section 2.3
9. The density of a solid is 1.36g/mL. The specific gravity of the substance is
A. 1.00
B. 1.40
C. 1.36
D. Cannot be determined
Answer: C; Difficulty: easy; Reference: Section 2.9
10. One kilometer is equal to
A. 0.001m
B. 0.01m
C. 100m
D. 1000m
Answer: D; Difficulty: easy; Reference: Section 2.5
11. One centigram is equal to
A. 0.001g
B. 0.01g
C. 100g
D. 1000g
Answer: B; Difficulty: easy; Reference: Section 2.5
12. One millimeter is equal to
A 0.001m
B. 0.01m
C. 100m
D. 1000m
Answer: A; Difficulty: easy; Reference: Section 2.5
13. The temperature of 400. degrees Celsius is equal to
A. 127 K
B. 163 K
C. 637 K
D. 673 K
Answer: D; Difficulty: easy; Reference: Section 2.8
14. The temperature of -100. degrees Celsius is equal to
A. -173 K
B. -137 K
C. 137 K
D. 173 K
Answer: D; Difficulty: easy; Reference: Section 2.8
15. A temperature of 100 K is equal to which Celsius temperature?
A. -173
B. -137
C. 237
D. 273
Answer: A; Difficulty: easy; Reference: Section 2.8
16. The temperature of 40.0 degrees Fahrenheit is equal to which Celsius temperature?
A. 4.44
B. 20.0
C. 45.0
D. 115
Answer: A; Difficulty: medium; Reference: Section 2.8
17. The temperature of 40.0 degrees Celsius is equal to which Fahrenheit temperature?
A. 23.0
B. 13.0
C. 74.0
D. 104
Answer: D; Difficulty: medium; Reference: Section 2.8
18. When the Celsius temperature changes 40. degrees, the Kelvin temperature will change
A. 40 degrees
B. 277 degrees
C. 313 degrees
D. 72 degrees
Answer: A; Difficulty: easy; Reference: Section 2.8
19. A piece of metal has a mass of 86.24g and a volume of 13.4mL. What is its density?
A. 0.155g/mL
B. 6.44g/mL
C. 72.8g/mL
D. 99.6g/mL
Answer: B; Difficulty: easy; Reference: Section 2.9
20. A liquid has a mass of 40.24g and a volume of 50.0mL. What is its density?
A. 0.805g/mL
B. 1.24g/mL
C. 9.76g/mL
D. 90.2g/mL
Answer: A; Difficulty: easy; Reference: Section 2.9
21. A solid substance has a density of 4.36g/mL. What is the volume of 30.0g of this substance?
A. 0.145mL
B. 6.88mL
C. 34.36mL
D. 131mL
Answer: B; Difficulty: medium; Reference: Section 2.9
22. A liquid has a density of 1.27g/mL. What is the mass of 20.0mL of this liquid?
A. 0.0635g
B. 15.7g
C. 21.27g
D. 25.4g
Answer: D; Difficulty: medium; Reference: Section 2.9
23. Convert 3.00 yards into centimeters.
A. 22.9cm
B. 43.2cm
C. 254cm
D. 274cm
Answer: D; Difficulty: easy; Reference: Section 2.6
24. Convert 3.00 feet into centimeters.
A. 10.2cm
B. 14.2cm
C. 25.4cm
D. 91.4cm
Answer: D; Difficulty: medium; Reference: Section 2.6
25. Convert 3.00 inches into centimeters.
A. 1.18cm
B. 2.54cm
C. 7.62cm
D. 10.2cm
Answer: C; Difficulty: easy; Reference: Section 2.6
26. Convert 3.00 centimeters into inches.
A. 1.18 inches
B. 2.54 inches
C. 7.62 inches
D. 10.2 inches
Answer: A; Difficulty: easy; Reference: Section 2.6
27. Which SI unit is most appropriate to measure the distance between Chicago and Detroit?
A. Millimeter
B. Centimeter
C. Meter
D. Kilometer
Answer: D; Difficulty: medium; Reference: Section 2.5
28. Which SI unit is most appropriate to measure the thickness of a dime?
A. Meter
B. Millimeter
C. Decimeter
D. Kilometer
Answer: B; Difficulty: medium; Reference: Section 2.5
29. Multiply (40.36) by (37.4). The product expressed to the proper number of significant figures
is
A. 151
B. 1509
C. 1510
D. 1509.464
Answer: C; Difficulty: easy; Reference: Section 2.4
30. Divide 1436 by 203. The quotient expressed to the proper number of significant figures is
A. 0.141
B. 0.1414
C. 7.07
D. 7.074
Answer: C; Difficulty: easy; Reference: Section 2.4
31. Add 114.32 + 12.1 + 13. The sum expressed to the proper number of significant figures is
A. 139
B. 139.4
C. 139.42
D. 140
Answer: A; Difficulty: easy; Reference: Section 2.4
32. Subtract 14.3 from 130.670. The difference expressed to the correct number of significant
figures is
A. 116
B. 116.3
C. 116.4
D. 116.37
Answer: C; Difficulty: easy; Reference: Section 2.4
33. How many significant figures should be included in the answer to the following calculation?
(3.48) (3.6) / 2.470
A. 1
B. 2
C. 3
D. 4
Answer: B; Difficulty: easy; Reference: Section 2.4
34. How many significant figures should be included in the answer to the following calculation?
(3.60) (2.489) (5.1110)
A. 2
B. 3
C. 4
D. 5
Answer: B; Difficulty: easy; Reference: Section 2.4
35. How many significant figures should be included in the answer to the following calculation?
(3.4876) / (4.11)
A. 2
B. 3
C. 4
D. 5
Answer: B; Difficulty: easy; Reference: Section 2.4
36. How many zeroes are significant in the number 0.0040?
A. 1
B. 2
C. 3
D. 4
Answer: A; Difficulty: medium; Reference: Section 2.3
37. How many zeroes are significant in the number 0.03003?
A. 1
B. 2
C. 3
D. 4
Answer: B; Difficulty: medium; Reference: Section 2.3
38. How many zeroes are significant in the number 40400302?
A. 1
B. 2
C. 3
D. 4
Answer: D; Difficulty: medium; Reference: Section 2.3
39. How many zeroes are significant in the number 30000.?
A. 1
B. 2
C. 3
D. 4
Answer: D; Difficulty: medium; Reference: Section 2.3
40. What number is indicated by the SI prefix milli?
A. 1/100
B. 1/1000
C. 100
D. 1000
Answer: B; Difficulty: easy; Reference: Section 2.5
41. Convert 4.30 feet into centimeters.
A. 10.9cm
B. 30.5cm
C. 131cm
D. 151cm
Answer: C; Difficulty: medium; Reference: Section 2.6
42. Convert 10.00 grams into decigrams.
A. 1.000dg
B. 10.00dg
C. 100.0dg
D. 1000.dg
Answer: C; Difficulty: medium; Reference: Section 2.5
43. The density of copper is 8.96g/mL. The mass of 7.00mL of copper is
A. 62.7g
B. 1.28g
C. 0.781g
D. 1.96g
Answer: A; Difficulty: medium; Reference: Section 2.9
44. The density of copper is 8.96g/mL. The volume of 12.0g of copper is
A. 0.747g
B. 1.34g
C. 3.04g
D. 108g
Answer: B; Difficulty: medium; Reference: Section 2.9
45. The mass of a substance is 17.46g and its volume is 3.42mL. What is the density of the
substance rounded to the correct number of significant figures?
A. 0.1959g/mL
B. 0.196g/mL
C. 5.105g/mL
D. 5.11g/mL
Answer: D; Difficulty: medium; Reference: Section 2.3 and 2.9
46. Convert 30.0 milliliters to Liters.
A. 0.0300L
B. 0.00300L
C. 300.L
D. 30000L
Answer: A; Difficulty: easy; Reference: Section 2.5
47. The space occupied by a sample is its
A. Mass
B. Volume
C. Length
D. Temperature
Answer: B; Difficulty: easy; Reference: Section 2.9
48. If the Celsius temperature of a sample changes twenty degrees, how many degrees does its
Kelvin temperature change?
A. 20
B. 257
C. 273
D. 293
Answer: A; Difficulty: easy; Reference: Section 2.8
49. A rectangular piece of metal measures 8.0cm by 1.20m by 15.0mm. What is its volume
rounded to the correct number of significant figures?
A. 14cm3
B. 144cm3
C. 1400cm3
D. 1440cm3
Answer: C; Difficulty: easy; Reference: Section 2.4
50. A cube measures 13.00cm on edge. What is its volume?
A. 13.00cm3
B. 169.0cm3
C. 2197cm3
D. 28600cm3
Answer: C; Difficulty: easy; Reference: Section 2.4
51. A metal cube measures 8.60cm on edge and has a density of 11.4g/cm3. What is its mass?
A. 98.0g
B. 843g
C. 7250g
D. 62400g
Answer: C; Difficulty: medium; Reference: Section 2.9
52. A 48.0g piece of metal is dropped into 50.0mL of water in a graduated cylinder. The water
level rises to 62.4mL. What is the density of the metal?
A. 12.4mL
B. 0.258mL/g
C. 3.87g/mL
D. 595gmL
Answer: C; Difficulty: medium; Reference: Section 2.9
53. One centimeter is equal to
A. 2.54 inches
B. 0.394 inches
C. 12.0 inches
D. 0.100 inches
Answer: B; Difficulty: easy; Reference: Section 2.6
54. An empty graduated cylinder has a mass of 68.00g. 50.0mL of water is added to the cylinder
and its mass increases to 109.5g. What is the density of the liquid?
A. 41.5g
B. 1.20mL/g
C. 0.830g/mL
D. 1.36g/mL
Answer: C; Difficulty: medium; Reference: Section 2.9
55. A car gets 25.6 miles per gallon of gasoline. A full tank of gasoline contains 56.8 liters.
How many miles can this car travel on a full tank of gasoline? ( 1.000L = 1.057qt )
A. 1454 miles
B. 96.9 miles
C. 1.71 miles
D. 384 miles
Answer: D; Difficulty: medium; Reference: Section 2.6
56. Convert 4.34 yards to centimeters.
A. 4.34cm
B. 132cm
C. 264cm
D. 397cm
Answer: D; Difficulty: hard; Reference: Section 2.6
57. The number of centimeters in one inch is
A. 0.109
B. 0.328
C. 0.394
D. 2.54
Answer: D; Difficulty: easy; Reference: Section 2.6
58. Add: 3.604m + 104.29m + 3.1m + 17.41m. The sum expressed in the correct number of
significant figures is
A. 13m
B. 128m
C. 130m
D. 128.4m
Answer: D; Difficulty: easy; Reference: Section 2.4
59. Subtract: 14.278m from 106.31m. The difference expressed in the correct number of
significant figures is
A. 92.032m
B. 92.03m
C. 92.0m
D. 92m
Answer: B; Difficulty: easy; Reference: Section 2.4
60. Multiply: (3.687) (14.1) (36.22). The product expressed in the correct number of significant
figures is
A. 1882.9583
B. 188
C. 1883.0
D. 1880
Answer: D; Difficulty: easy; Reference: Section 2.4
61. Divide: 34.72 by 4.7. The quotient expressed to the correct number of significant figures is
A. 0.14
B. 0.1
C. 7.39
D. 7.4
Answer: D; Difficulty: easy; Reference: Section 2.4
62. Divide: 32.14 by 0.204. The quotient expressed to the correct number of significant figures
is
A. 157.55
B. 158
C. 6347
D. 6350
Answer: B; Difficulty: easy; Reference: Section 2.4
63. When expressed in proper scientific notation the number 4289 is
A. 4.289 X 10-4
B. 4.289 X 10-3
C. 4.289 X 103
D. 4.289 X104
Answer: C; Difficulty: easy; Reference: Section 2.1
64. When expressed in proper scientific notation the number 286 is
A. 2.86 X 101
B. 2.86 X 102
C. 2.86 X 10-2
D. 28.6 X 101
Answer: B; Difficulty: easy; Reference: Section 2.1
65. When expressed in proper scientific notation the number 0.00364 is
A. 3.64 X 103
B. 3.64 X 102
C. 3.64 X 10-2
D. 3.64 X 10-3
Answer: D; Difficulty: easy; Reference: Section 2.1
66. When expressed in proper scientific notation the number 0.000034 is
A. 3.4 X 104
B. 3.4 X 10-4
C. 3.4 X 103
D. 3.4 X 10-5
Answer: D; Difficulty: easy; Reference: Section 2.1
67. Express the number 2.64  104 in decimal notation
A. 0.000264
B. 0.0000264
C. 26400
D. 2640
Answer: C; Difficulty: easy; Reference: Section 2.1
68. Express the number 3.00  102 in decimal notation
A. 3.00
B. 30.0
C. 300.
D. 3000.
Answer: C; Difficulty: easy; Reference: Section 2.1
69. Express the number 4.317  10-4 in decimal notation
A. 0.04317
B. 0.004317
C. 0.0004317
D. 43170
Answer: C; Difficulty: easy; Reference: Section 2.1
70. Express the number 5.0  10-2 in decimal notation
A. 500
B. 50
C. 0.050
D. 0.0050
Answer: C; Difficulty: easy; Reference: Section 2.1
71. Multiply: ( 4.36  10-2 ) ( 3.17  104 ). When expressed properly the product is
A. 1.38 X 103
B. 1.38 X 102
C. 1.38 X 10-2
D. 1.38 X 105
Answer: A; Difficulty: easy; Reference: Section 2.4
72. Multiply: ( 5.24  104 ) ( 2.36  10-5 ). When expressed properly the product is
A. 1.24 X 10-1
B. 1.24 X 100
C. 1.24 X 101
D. 1.24 X 109
Answer: B; Difficulty: easy; Reference: Section 2.4
73. Divide: 3.724  10-3 by 2.46  104. When expressed properly the result is
A. 1.51 X 101
B. 1.51 X 10-7
C. 6.61 X 101
D. 6.61 X 102
Answer: B; Difficulty: easy; Reference: Section 2.4
74. Divide: 4.863  104 by 2.12  104. When expressed properly the result is
A. 4.36 X 10-1
B. 4.36 X 108
C. 2.29 X 108
D. 2.29 X 100
Answer: D; Difficulty: easy; Reference: Section 2.4
75. Perform the following set of operations and choose the alternative that expresses the result to
the proper number of significant figures.
65.43 - 43.2
1.232 x 10-3
–4
A. 1.80 x 10
B. 1.804 x 104
C. 1.80 x 104
D. 1.8 x 104
Answer: C; Difficulty: hard; Reference: Section 2.4
76. Perform the following set of operations and choose the alternative that expresses the result to
the proper number of significant figures.
3.45 x102  2.31x 1
0.044
A. 6.0
B. 6.03
C. 6.034
D. 6
Answer: A; Difficulty: hard; Reference: Section 2.4
77. Perform the following set of operations and choose the alternative that expresses the result to
the proper number of significant figures.
54.331
2.345  1.521
A. 65.94
B. 65
C. 70
D. 65.9
Answer: D; Difficulty: hard; Reference: Section 2.4
78. Convert 12.5 m3 to cm3.
A. 1.25 x 103 cm3
B. 1.25 x 107 cm3
C. 1.25 x 105 cm3
D. 1.25 x 10–3 cm3
Answer: B; Difficulty: hard; Reference: Section 2.6
79. Convert 76.9 L to cm3.
A. 76900 cm3
B. 7690 cm3
C. 76900000 cm3
D. 769000 cm3
Answer: A; Difficulty: hard; Reference: Section 2.6
80. Convert 33.0 inch2 to mm2.
A. 2.13 x 103 mm2
B. 8.38 x 102 mm2
C. 2.13 x 104 mm2
D. 5.12 x 102 mm2
Answer: C; Difficulty: hard; Reference: Section 2.6
81. An empty jar weighs 1.43 pounds. How much will it weigh when 1.00 L of homogenized
milk is poured into it? The density of homogenized milk is 1.03 g/mL. (1 pound = 453.6 g)
A. 442 pounds
B. 3.57 pounds
C. 2.46 pounds
D. 3.70 pounds
Answer: D; Difficulty: hard; Reference: Section 2.9
82. An empty glass tube weighs 37.3 g. When filled to the rim with water, it weighs 54.1 g. What
is the volume of the glass tube?
A. 16.8 cm3
B. 54.1 cm3
C. 37.3 cm3
D. 91.4 cm3
Answer: A; Difficulty: hard; Reference: Section 2.9
83. How many grams of iron (density = 7.87 g/mL ) would occupy the same volume as 96.4 g of
aluminum (density = 2.70 g/mL)?
A. 4.54 g
B. 33.1 g
C. 281 g
D. 220. g
Answer: C; Difficulty: hard; Reference: Section 2.9
84. If you travel to Canada, speed limits are posted in km/hr. For a speed limit of 70. mi/hr, what
would be the speed limit posted on a Canadian highway? (1 mile = 1.609 km)
A. 110 km/hr
B. 44 km/hr
C. 68 km/hr
D. 72 km/hr
Answer: A; Difficulty: hard; Reference: Section 2.6
85. A police car on a high-speed chase travels at a speed of 85 mi/hr. The chase covered 82.3
miles of roadway. For how long were the police chasing the suspects?
A. 63 minutes
B. 58 minutes
C. 291 minutes
D. 97 minutes
Answer: B; Difficulty: easy; Reference: Section 2.6
86. The speed of light is 2.9987 x 108 m/s. Convert this speed to km/hr.
A. 1.0795 x 109 km/hr
B. 1.7992 x 107 km/hr
C. 8.3297 x 101 km/hr
D. 8.3297 x 104 km/hr
Answer: A; Difficulty: hard; Reference: Section 2.6
87. Calculate the density (in g/mL) of an unknown substance if 0.897 pounds occupy 13.5 inch3.
A. 1.84 g/mL
B. 11.9 g/mL
C. 2.29 g/mL
D. 1.09 g/mL
Answer: A; Difficulty: hard; Reference: Section 2.9
88. The following alternatives represent numbers that were expressed to three significant figures.
Which of the alternatives is expressed incorrectly?
A. 45.7899 to 45.8
B. 890.332 to 891
C. 0.002346 to 0.00235
D. 1543456 to 1.54 x 106
Answer: B; Difficulty: medium; Reference: Section 2.4
True/False
89. The mass of a substance depends on gravity.
Answer: False; Difficulty: easy; Reference: Section 2.7
90. The weight of a substance depends on gravity.
Answer: True; Difficulty: easy; Reference: Section 2.7
91. A solid with a lower density will float on a liquid with a higher density.
Answer: True; Difficulty: easy; Reference: Section 2.9
92. If two substances have the same mass, the one with the greater volume will have the greater
density.
Answer: False; Difficulty: hard; Reference: Section 2.9
93. The prefix kilo means 1000.
Answer: True; Difficulty: easy; Reference: Section 2.5
94. A solid with a specific gravity of 0.800 will float in water.
Answer: True; Difficulty: medium; Reference: Section 2.9
95. The meter is a unit of length.
Answer: True; Difficulty: easy; Reference: Section 2.7
96. The mass of a substance is independent of its location.
Answer: True; Difficulty: easy; Reference: Section 2.7
97. The density of liquid A is 2.14g/mL and the density of liquid B is 1.46g/mL. When equal
masses of these liquids are compared, liquid A will have the greater volume.
Answer: False; Difficulty: hard; Reference: Section 2.9
98. A volume of 300.mL is the same as a volume of 30.0cm3.
Answer: False; Difficulty: easy; Reference: Section 2.6
99. Two substances A and B occupy the same volume. The mass of substance A is half that of
substance B. Therefore, the density of substance A is lower than the density of substance B.
Answer: True; Difficulty: hard; Reference: Section 2.9
100. Two substances A and B have the same mass. Substance A occupies half the volume of
substance B. Therefore, the density of substance A is lower than the density of substance B.
Answer: False; Difficulty: hard; Reference: Section 2.9
101. The significant figures in a number include all the digits that are certain plus the first
uncertain digit.
Answer: True; Difficulty: easy; Reference: Section 2.3
102. The kilogram is the SI unit for mass.
Answer: True; Difficulty: easy; Reference: Section 2.7
Free Response
103. A student determines the density of a solid by weighing it and then immersing it in 50.0mL of
water in a graduated cylinder.
The following data is obtained:
Weight
Volume of water and solid
39.364g
58.0mL
Answer the following based on the preceding information. Answers should have units and be
rounded to the proper number of significant figures.
A. What is the volume of the solid?
B. What is the density of the solid?
C. What is the specific gravity of the solid?
D. Will the solid float or sink in water?
Answer: A. The volume of the solid is 8.0 mL; B. The density of the solid is 4.9g/mL; C. The
specific gravity of the solid is 4.9; D. The solid will sink in water; Difficulty: easy; Reference:
Section 2.9
104. A student determines the density of a liquid by weighing an empty graduated cylinder,
adding 50.0mL of liquid to the cylinder and weighing the cylinder and liquid.
The following data is obtained:
Weight of the empty cylinder
Weight of the cylinder and liquid
63.416g
104.312g
Answer the following based on the preceding information. Answers should have units and be
rounded to the proper number of significant figures.
A. What is the mass of the liquid?
B. What is the density of the liquid?
C. What is the specific gravity of the liquid?
D. Will the liquid float or sink in water?
Answer: A. The mass of the liquid is 40.90g; B. The density of the liquid is 0.818g/mL; C. The
specific gravity of the liquid is 0.818; D. The liquid will float on water; Difficulty: easy;
Reference: Section 2.9
105. A. What is the difference between mass and weight?
B. Which property, mass or weight, is better to use in science to describe a substance?
Why is this true?
C. What instruments are used to measure mass and weight?
Answer: Mass is the amount of matter present in an object. Weight is a measure of the earth’s
gravitational attraction on an object; B. It is better to use mass to describe a substance. Mass is
better to use because it does not vary in different gravitational fields. Weight varies as the force of
gravity changes; C. Mass is measured with a balance. Weight is measured with a scale; Difficulty:
medium; Reference: Section 2.7
106. The density of ethanol is 0.7893g/mL. What is the mass of one pint of ethanol?
Answer: The mass of one pint of ethanol is 373.4g; Difficulty: hard; Reference: Section 2.9
107. A rectangular solid has a mass of 1.490 kilograms. The solid measures 4.3cm by 10.6cm by
13.6cm. Calculate the density of the solid and express it to the correct number of significant figures
in g/cm3.
Answer: The density of the solid is 2.4g/cm3.; Difficulty: medium; Reference: Section 2.9
108. Of these three: four degrees Fahrenheit, four degrees Kelvin, and minus four degrees Celsius,
which is the warmest?
Answer: The warmest temperature is minus four degrees Celsius; Difficulty: medium; Reference:
Section 2.8
109. What is the appropriate SI unit to express each of the following properties?
A. The surface area of a gymnasium floor.
B. The volume of air in a dining room.
C. The thickness of a quarter.
D. The volume of liquid in a wine bottle.
E. The height of a redwood tree.
F. The heat energy in a thermos of hot coffee.
G. The mass of a large textbook.
Answer: A. Square meters; B. Cubic meters; C. Millimeters; D. Milliliters or cubic centimeters;
E. Meters; F. Kilojoules; G. Kilograms; Difficulty: medium; Reference: Section 2.5
110. Explain how an ocean of water and a cup of the same ocean water can have the same
temperature but contain different amounts of heat.
Answer: Temperature is the average kinetic energy of the molecules in a sample. If both samples
have the same temperature they consist of molecules with the same average kinetic energy. The
sample with more molecules, the ocean, must have the greater total amount of energy; Difficulty:
hard; Reference: Section 2.8
Chapter 2: Atoms, Ions, and the Periodic Table
1. Which of the following were the elements according to the early Greeks?
A) earth, wind, and fire
D) sun, sand, and water
B) earth, air, fire, and water
E) none of these
C) carbon, hydrogen, and oxygen
Ans: B
2. Which of the following statements regarding atoms and atomic theory is incorrect?
A) “Atomos” is a Greek word meaning unbreakable.
B) Democritus, a Greek philosopher, believed that matter could be broken down into
infinitely small pieces.
C) The ancient Greeks believed that all matter is made of four elements: earth, air, fire,
and water.
D) An element is a substance that cannot be broken down into simpler substances.
E) By the 1700s, all chemists believed that elements were made of atoms.
Ans: E
3. Which of the following statements regarding atoms and atomic theory is incorrect?
A) Antoine Lavoisier discovered in the late 1700s that matter is not gained or lost in a
chemical reaction.
B) Joseph Proust showed that when elements combine to form new substances, they do
so in specific mass ratios.
C) According to the law of multiple proportions, when water forms, the mass ratio of
hydrogen to oxygen is variable.
D) John Dalton's atomic theory disagreed with the ancient Greek philosophers' ideas
about matter.
E) The Greek philosophers did not conduct experiments to support their ideas.
Ans: C
4. The figure shows a molecular-level diagram of the chemical reaction between hydrogen and
nitrogen to form ammonia. What is wrong with this diagram?
A)
B)
C)
D)
E)
The products contain more nitrogen atoms than the reactants.
The products contain more hydrogen atoms than the reactants.
The number of reactant molecules should equal the number of product molecules.
The products should contain some unreacted hydrogen.
The product ammonia molecules should have only two hydrogen atoms attached to
nitrogen.
Ans: B
5. Which of the following elements is not one of the three most abundant elements in the
human body?
A) carbon B) oxygen C) iron D) hydrogen
Ans: C
6. Which of the following statements is incorrect?
A) The human body is made up of about 99% carbon, hydrogen, and oxygen.
B) Essential minerals come from the foods we eat and drink.
C) Most of the essential minerals in our diet are classified as metals on the periodic table.
D) Minerals are necessary for the growth and production of bones, teeth, blood, etc.
E) Magnesium is a building-block for hemoglobin, which carries oxygen in our blood.
Ans: E
7. Which of the following observations does not relate specifically to the law of definite
proportions?
A) Pure water is composed of the elements oxygen and hydrogen in a mass ratio of 8 to 1.
B) Any sample of a given compound always contains the same proportions by mass of
the component elements.
C) The mass of the products of a chemical reaction is equal to the mass of the starting
materials of the reaction.
D) When a metal reacts with oxygen, the oxygen content of the products is fixed at one or
two values.
E) When water is broken down into its elements by electrolysis, elemental oxygen and
hydrogen are formed in an 8 to 1 mass ratio.
Ans: C
8. Which of the following is not part of Dalton's atomic theory?
A) All matter is composed of small indivisible particles called atoms.
B) All atoms of a given element have identical mass and chemical properties.
C) Atoms of one element can be changed to atoms of another element in a chemical
reaction.
D) Atoms combine in whole-number ratios to form chemical compounds.
E) Chemical reactions involve a rearrangement of the atoms in the starting materials.
Ans: C
9. Which of the following statements regarding atomic theory is incorrect?
A) John Dalton's experimental results led to the law of conservation of mass.
B) Antoine Lavoisier's experiments showed that the mass of the products of a chemical
reaction equals the mass of the reacting substances.
C) When wood is burned, the ashes weigh less than the original wood, but this is not a
violation of the law of conservation of matter.
D) Dalton's atomic theory says that a chemical reaction is a rearrangement of atoms into
one or more different chemical substances.
E) Joseph Proust's findings regarding the reactions between metals and oxygen led to the
law of definite proportions.
Ans: A
10. Dalton's atomic theory consisted of all the following postulates except
A) Elements are composed of indivisible particles called atoms.
B) Atoms of different elements have different properties.
C) The volumes of gases that combine are in small whole number ratios.
D) Atoms combine in fixed ratios of whole numbers when they form compounds.
E) In chemical reactions, atoms are not created or destroyed.
Ans: C
11. Rutherford's scattering experiment demonstrated
A) the existence of protons.
B) the existence of electrons.
C) the existence of neutrons.
D) that most of the mass of an atom is in its nucleus.
E) that the charge-to-mass ratio of an electron is constant.
Ans: D
12. For the SO3 molecule, the Law of Definite Proportions requires that the mass ratio of S to O
must be
A) 32:16 B) 32:32 C) 32:48 D) 16:32 E) 16:8
Ans: C
13. The subatomic particles of interest to chemists, that make up the atom, include all of the
following except the:
A) proton.
D) neutron.
B) alpha particle.
E) alpha particle and neutron.
C) electron.
Ans: B
14. In any neutral atom:
A) the number of electrons equals the number of protons.
B) the number of electrons is less than the number of protons.
C) the number of electrons is greater than the number of protons.
D) the number of electrons is equal to the number of neutrons.
E) the number of neutrons is always equal to the number of protons.
Ans: A
15. An atom contains
A) as many neutrons as electrons.
B) as many protons as neutrons.
C) as many nuclei as electrons.
Ans: D
D)
E)
as many electrons as protons.
no protons.
16. Which of the following statements regarding the nucleus of the atom is incorrect?
A) The nucleus is the central core of the atom.
B) The nucleus contains the electrons and the protons.
C) The nucleus contains most of the mass of the atom.
D) The nucleus contains the neutrons.
E) The nucleus contains the neutrons and protons and most of the mass of the atom.
Ans: B
17. Which particles are found in the atomic nucleus?
A) Protons and electrons
D) Only electrons
B) Electrons and neutrons
E) Only neutrons
C) Protons and neutrons
Ans: C
18. The number of ________ determines the identity of an element.
A) electrons
D) neutrons plus protons
B) protons
E) protons plus electrons
C) neutrons
Ans: B
19. The atomic number of an element represents
A) the number of electrons its atom can gain.
B) the number of neutrons in an atom of the element.
C) the number of protons in an atom of the element.
D) the number of protons and neutrons in an atom of the element.
E) the mass of an atom of the element.
Ans: C
20. The mass number of an atom represents
A) the number of electrons in that atom.
B) the number of isotopes of that atom.
C) the number of neutrons in that atom.
D) the number of protons in that atom.
E) the number of protons and neutrons in that atom.
Ans: E
21. Which of the following is the same for isotopes of an element?
A) mass number
B) mass of an atom
C) neutron number
D) atomic number
E) both atomic number and neutron number
Ans: D
22. Which of the following statements about isotopes is incorrect?
A) The isotopes of an element have the same number of protons, but different numbers of
neutrons.
B) 1H, 2H, and 3H are all isotopes of hydrogen.
C) Isotopes of an element have similar chemical properties.
D) The melting point and boiling point of different isotopes of the same element will
vary greatly.
E) The different isotopes of an element have different mass numbers.
Ans: D
23. What do the following have in common?
17 – 18
Cl , Ar, and 19K+
A) Number of protons
B) Number of neutrons
C) They are isotopes.
Ans: D
D)
E)
Number of electrons
They are all ions.
24. Atoms of different isotopes of a given element have the same
A) number of electrons.
B) sum of the number of protons and neutrons.
C) sum of the number of electrons and neutrons.
D) sum of the number of electrons, protons, and neutrons.
E) mass numbers.
Ans: A
25. The element magnesium, Mg, has three common isotopes: 24Mg, 25Mg, and 26Mg. The
difference between these three isotopes is
A) the number of neutrons.
D) the number of protons and electrons.
B) the number of electrons.
E) their physical state.
C) the number of protons.
Ans: A
26. The correct isotope symbol for the isotope in the figure is:
A) 146 C
Ans: C
B)
14
7
N
C)
13
7
N
D)
20
14
Si
E)
15
7
N
27. The correct isotope symbol for the isotope in the figure is:
A) 42 He
Ans: B
B)
3
2
He
C)
3
1
H
D)
5
2
He
E)
5
3
Li
28. The number of neutrons in an atom of I-131 is:
A) 131 B) 78 C) 53 D) 77 E) insufficient information given
Ans: B
29. The number of neutrons in an atom of copper-65 is:
A) 65 B) 29 C) 84 D) 36 E) insufficient information given
Ans: D
30. The number of neutrons in an atom of uranium-235 is:
A) 235 B) 92 C) 327 D) 143 E) insufficient information given
Ans: D
31. The number of protons and neutrons in an atom of bromine-81 is:
A) 81 protons and 35 neutrons.
C) 46 protons and 35 neutrons.
B) 35 protons and 81 neutrons.
D) 35 protons and 46 neutrons.
Ans: D
32. The number of protons and neutrons in an atom of argon-38 is:
A) 38 protons and 18 neutrons.
D) 38 protons and 56 neutrons.
B) 18 protons and 20 neutrons.
E) 18 protons and 56 neutrons.
C) 18 protons and 38 neutrons.
Ans: B
33. The number of protons and neutrons in an atom of magnesium-25 is:
A) 25 protons and 12 neutrons.
D) 12 protons and 13 neutrons.
B) 12 protons and 25 neutrons.
E) 13 protons and 12 neutrons.
C) 25 protons and 37 neutrons.
Ans: D
34. Identify the element or ion shown in the figure.
A) 18Ne2+
Ans: B
B)
18
O
C)
18
Ar D)
10
O2
E)
16
O
35. The overall charge of an atom is ________ if the number of electrons is ________ than the
number of protons.
A) negative, less B) negative, greater C) positive, greater D) neutral, less
Ans: B
36. The overall charge of an atom is ________ if the number of electrons is ________ than the
number of protons.
A) negative, less B) positive, greater C) positive, less D) neutral, less
Ans: C
37. List the number of protons, neutrons, and electrons for 40Ca2+:
A) 40 protons, 20 neutrons, and 20 electrons
B) 40 protons, 20 neutrons, and 18 electrons
C) 20 protons, 20 neutrons, and 18 electrons
D) 20 protons, 20 neutrons, and 22 electrons
E) 60 protons, 20 neutrons, and 18 electrons
Ans: C
38. List the number of protons, neutrons, and electrons for 35Cl:
A) 35 protons, 18 neutrons, and 18 electrons
B) 18 protons, 17 neutrons, and 17 electrons
C) 17 protons, 18 neutrons, and 18 electrons
D) 17 protons, 18 neutrons, and 17 electrons
E) 52 protons, 18 neutrons, and 18 electrons
Ans: C
39. List the number of protons, neutrons, and electrons for 37Cl:
A) 37 protons, 19 neutrons, and 18 electrons
B) 20 protons, 17 neutrons, and 17 electrons
C) 17 protons, 20 neutrons, and 18 electrons
D) 17 protons, 18 neutrons, and 20 electrons
E) 54 protons, 17 neutrons, and 18 electrons
Ans: C
40. Which one of the following has as many electrons as it has neutrons?
A) 1H B) 40Ca2+ C) 12C D) 19F E) 14C4–
Ans: C
41. Which one of the following has more neutrons than protons?
A) 38Ca B) 15O C) 19F D) 36Ar E) 12N
Ans: C
42. Which of the following contains 18 neutrons?
A) 31P B) 34S2– C) 36Cl D) 80Br– E) 18O
Ans: B
43. How many protons, neutrons, and electrons are in an atom of 197Au, the most common
isotope of gold?
A) 197, 79, 118
D) 79, 118, 118
B) 118, 79, 79
E) 79, 118, 79
C) 79, 197, 79
Ans: E
44. The isotope symbol for an ion that has 13 protons, 14 neutrons, and 10 electrons is:
13
3+
Si 4+ C) 27
A) 14
B) 14
D) 27
E) none of these
13 Al
13 Al
13 Al
Ans: D
45. The isotope symbol for an ion that has 11 protons, 12 neutrons, and 10 electrons is:
+
+
23
Mg 2+
A) 12
B) 12
C) 23
D) 23
E) 12
11 Na
11 Na
11 Na
11 Na
Ans: C
46. The isotope symbol for an ion that has 12 protons, 12 neutrons, and 10 electrons is:
2
2
A) 12
B) 12
C) 24
D) 24
E) none of these
10 Mg
12 Ne
12 Mg
12 Mg
Ans: C
47. Which of the following statements regarding relative atomic masses is incorrect?
A) Relative atomic mass is one of the numbers that appears on a typical periodic table.
B) The average mass of the individual isotopes of an element considering the natural
abundance of each is the relative atomic mass of that element.
C) The relative atomic mass of carbon is 12.01 amu because carbon-12 is the most
abundant isotope, with smaller amounts of carbon-13 and carbon-14.
D) The terms “mass number” and “relative atomic mass” can be used interchangeably.
E) Mass spectrometry is used to find the mass of each isotope of an element, and
measure their abundance.
Ans: D
48. On the planet Melmac, in a galaxy far, far away, argon has three naturally occurring
isotopes as follows:
Isotope
Mass (amu)
Natural Abundance (%)
Argon-40
39.962
74.20
Argon-38
37.963
15.15
Argon-36
35.968
10.65
What is the relative atomic mass of argon on Melmac?
A) 39.23 amu B) 39.96 amu C) 37.96 amu D) 35.97 amu E) 40.00 amu
Ans: A
49. On the planet Invertios, boron has two isotopes as follows:
Isotope
Mass (amu) Natural Abundance (%)
Boron-10
10.0129
80.00
Boron-11
11.0093
20.00
Estimate the relative atomic mass of boron on Invertios.
A) 10.0 amu B) 10.2 amu C) 10.5 amu D) 10.8 amu
Ans: B
E) 11.0 amu
50. An element, El, has two isotopes with the following masses and abundances:
38
El 38.012 amu 75.68%
46
El 45.974 amu 24.32%
What is the identity of this element?
A) Ar B) K C) Ca D) S E) Cl
Ans: A
51. Naturally occurring copper consists of copper-63 (62.9296 amu), and copper-65 (64.9278
amu). Using the relative atomic mass from the periodic table, which of the following is the
best estimate of the percent abundance of the two isotopes of copper?
A) 50% copper-63 and 50% copper-65 D) 90% copper-63 and 10% copper-65
B) 75% copper-63 and 25% copper-65 E) 10% copper-63 and 90% copper-65
C) 25% copper-63 and 75% copper-65
Ans: B
52. Boron has two isotopes: B-10 and B-11, with masses of 10.013 amu and 11.009 amu,
respectively. The relative atomic mass of boron is 10.81 amu. Which statement best
describes the percent abundance of the isotopes of boron?
A) It contains more B-10 than B-11.
B) It contains more B-11 than B-10.
C) It contains equal amounts of B-10 and B-11.
D) There must be a third isotope of boron.
E) A mass spectrum of boron is necessary to answer this question.
Ans: B
53. Which of the following statements about Mendeleev's periodic table is incorrect?
A) Mendeleev arranged the known elements in order of increasing relative atomic mass.
B) He grouped elements with similar properties into columns and rows so that their
properties varied in a regular pattern.
C) He arranged the elements so that they were in increasing atomic number order.
D) He was able to predict the existence and properties of several elements that were
unknown at the time.
E) Mendeleev developed his table before the discovery of protons.
Ans: C
54. Which of the following statements about the modern periodic table in your text is
incorrect?
A) The periodic table is arranged by increasing atomic mass.
B) The elements are arranged in rows and columns to emphasize periodic properties.
C) Elements in the same vertical column are called groups or families.
D) Each group has a Roman numeral and a letter associated with it.
E) A horizontal row of elements is called a period.
Ans: A
55. A horizontal row of elements in the periodic table is called a:
A) group.
D) both group and family are correct.
B) family.
E) both group and period are correct.
C) period.
Ans: C
56. A vertical column in the periodic table is called a:
A) family or group. B) column. C) cohort. D) period.
Ans: A
E) covey.
57. Which of the following terms does not apply to the major categories of elements in the
periodic table?
A) metals
D) metalloids
B) antimetals
E) both antimetals and metalloids
C) nonmetals
Ans: B
58. Which of the following statements does not apply to metalloids?
A) The physical properties of metalloids resemble those of a metal.
B) All metalloids are electrical insulators.
C) Metalloids lie along the stair-step line beginning at boron.
D) The chemical properties of metalloids are similar to nonmetals.
E) Metalloids are also known as semi-metals.
Ans: B
59. Which of the following does not apply to the main-group elements?
A) Main-group elements are also known as representative elements.
B) Main-group elements are in groups labeled with the letter A.
C) Main-group elements are in groups labeled with the letter B.
D) Main-group elements include metals.
E) Main-group elements include nonmetals.
Ans: C
60. Sodium reacts vigorously with water to form hydrogen gas and a compound containing
sodium ions. Which other element is expected to react with water in a similar way?
A) hydrogen B) aluminum C) nitrogen D) potassium E) silicon
Ans: D
61. Elements in Group IA (1) (except hydrogen) are called:
A) alkaline earth metals.
D) nonmetals.
B) alkali metals.
E) halogens.
C) transition metals.
Ans: B
62. Elements in Group VIIA (17) are called:
A) halogens.
B) chalcogens.
C) noble gases.
Ans: A
63. Elements in Group IIA (2) are called:
A) halogens.
B) noble gases.
C) alkali metals.
Ans: D
64. Elements in Group VIIIA (18) are called:
A) halogens.
B) noble gases.
C) alkali metals.
Ans: B
D)
E)
inert gases.
alkali metals.
D)
E)
alkaline earth metals.
chalcogens.
D)
E)
alkaline earth metals.
chalcogens.
65. Which of the following statements applies to noble gases?
A) Noble gases exist as diatomic molecules in their elemental form.
B) Noble gases are found in Group VIIIA (18) in the periodic table.
C) Noble gases are very reactive.
D) Noble gases were discovered in ancient times.
E) Many compounds are known for each noble gas.
Ans: B
66. Which of the following statements regarding ion formation is incorrect?
A) Nonmetals usually gain electrons to form ions that have a noble gas electron count.
B) Main-group metals usually lose electrons to form ions that have a noble gas electron
count.
C) Elements in the same group often form ions of the same charge.
D) The charge of any element's ion can be simply predicted using the periodic table.
E) All of these statements are correct.
Ans: D
67. What changes when an ion is formed from an atom?
A) Neutrons are lost or gained.
B) Protons are lost or gained.
C) The nucleus disintegrates.
D) Electrons are lost or gained.
E) Either protons or electrons are lost or gained.
Ans: D
68. Which of the following is the most likely mass for an atom of bromine-81?
A) 81.000 amu
D) 81.331 amu
B) 80.875 amu
E) 81.500 amu
C) 80.916 amu
Ans: C
69. Which of the following is the most likely mass for an atom of silver-107?
A) 107.000 amu
D) 106.500 amu
B) 107.500 amu
E) 107.100 amu
C) 106.905 amu
Ans: C
70. Which of the following is the most likely mass for an atom of silver-109?
A) 109.000 amu
D) 108.905 amu
B) 108.500 amu
E) 109.100 amu
C) 108.000 amu
Ans: D
71. To the correct number of significant figures, the mass of exactly 250 atoms of mercury
would be:
A) 200.6 amu
D) 5.0100  104 amu
B) 250 amu
E) 1.246 amu
C) 5.015  104 amu
Ans: C
72. To the correct number of significant figures, the mass of exactly 200 atoms of carbon is:
A) 12.01 amu B) 24.02 amu C) 240.2 amu D) 2402 amu E) 16.65 amu
Ans: D
73. To the correct number of significant figures, the mass of exactly 400 atoms of magnesium
is:
A) 24.31 amu B) 9724 amu C) 97.24 amu D) 16.45 amu E) 0.06078 amu
Ans: B
74. When comparing 1000 amu of carbon atoms with 1000 amu of helium atoms:
A) each sample has the same number of atoms.
B) there are more carbon atoms than helium atoms.
C) there are more helium atoms than carbon atoms.
D) it is not possible to tell which sample contains more atoms.
E) helium is a gas, so it is less dense than the carbon, and therefore there would be fewer
atoms.
Ans: C
75. When comparing 10,000 amu of mercury atoms with 10,000 amu of iron atoms:
A) each sample has the same number of atoms.
B) there are more iron atoms than mercury atoms.
C) there are more mercury atoms than iron atoms.
D) it is not possible to tell which sample contains more atoms.
E) mercury is a liquid, so it would be less dense than the iron, and therefore there would
be fewer atoms.
Ans: B
76. When comparing a 10.00 g sample of iron with a 10.00 g sample of lead:
A) each sample has the same number of atoms.
B) there are more iron atoms than lead atoms.
C) there are more lead atoms than iron atoms.
D) it is not possible to tell which sample contains more atoms.
E) the lead is heavier than the iron, and therefore there would be more atoms.
Ans: B
77. Which set of elements below contains, respectively, an alkali metal, a halogen, and a
transition metal?
A) Rb, Br, Ag B) Ca, Kr, Mn C) Sc, Ba, I D) H, F, V E) Li, S, Fe
Ans: A
78. Which set of elements below contains, respectively, an alkaline earth metal, a noble gas, and
a metalloid?
A) Na, Ar, Si B) Ba, O, As C) Ti, Cl, Pb D) Bi, Kr, B E) Mg, Ne, Ge
Ans: E
79. Which set of elements below contains, respectively, an alkaline earth metal, a noble gas, and
a transition metal?
A) Ca, Ar, Pb B) Mg, N, Cu C) Sr, He, Ni D) Na, Xe, Fe E) Li, Rn, Cr
Ans: C
80. Which of the following elements does not naturally occur as a diatomic molecule?
A) oxygen B) nitrogen C) hydrogen D) neon E) bromine
Ans: D
81. Which of the following elements does not occur as a diatomic molecule?
A) iodine B) fluorine C) nitrogen D) hydrogen E) carbon
Ans: E
82. Which of the following elements does not occur as a diatomic molecule?
A) oxygen B) fluorine C) nitrogen D) neon E) iodine
Ans: D
83. To which class does the element chromium belong?
A) representative (main-group) elements D) actinides
B) transition elements
E) metalloids
C) lanthanides
Ans: B
84. To which class does the element uranium belong?
A) representative (main-group) elements D) actinides
B) transition elements
E) metalloids
C) lanthanides
Ans: D
85. To which class does the element calcium belong?
A) representative (main-group) elements D) actinides
B) transition elements
E) metalloids
C) lanthanides
Ans: A
86. Select the element that is an alkali metal in Period 3.
A) Na B) Mg C) Al D) K E) Ca
Ans: A
87. Select the element that is a halogen in Period 5.
A) Br B) Xe C) Te D) I E) N
Ans: D
88. Select the element that is an alkaline earth metal in Period 4.
A) Mg B) Sr C) K D) C E) Ca
Ans: E
89. In which group of the periodic table do the elements not form ions?
A) alkaline earth metals
D) noble gases
B) alkali metals
E) chalcogens
C) halogens
Ans: D
90. The ions of most main-group elements have the same number of ________ as the noble gas
that is closest to them in the periodic table.
A) neutrons
D) protons and electrons
B) protons
E) neutrons and electrons
C) electrons
Ans: C
91. The correct symbol for the ion formed by nitrogen is:
A) N2 B) N3 C) N3+ D) N2+ E) N
Ans: B
92. The correct symbol for the ion formed by sodium is:
A) Na+ B) S2 C) Na D) S2+ E) K+
Ans: A
93. The correct symbol for the ion formed by potassium is:
A) P3 B) P3+ C) K+ D) K E) P2
Ans: C
94. Calcium citrate is a compound found in some calcium supplement medications. The
calcium in this compound consists of ions containing 18 electrons. What is the charge of the
calcium ions?
A) –2 B) –1 C) +1 D) +2 E) +3
Ans: D
95. Calculate the relative atomic mass of speedium (a fictional element) which has three
isotopes with the following masses and abundances:
45
Sp 44.99 amu 30.0%
47
Sp 46.99 amu 60.0%
48
Sp 48.00 amu 10.0%
A) 45.0 amu B) 46.5 amu C) 46.7 amu D) 47.0 amu E) 140 amu
Ans: B
96. Antoine Lavoisier's experiments showed that the mass of the products of a chemical
reaction equals the mass of the reacting substances.
Ans: True
97. John Dalton's experimental results led to the law of conservation of mass.
Ans: False
98. When wood is burned, the ashes weigh less than the original wood, so this is a violation of
the law of conservation of mass.
Ans: False
99. Dalton's atomic theory says that a chemical reaction is a rearrangement of atoms into one or
more different chemical substances.
Ans: True
100. All of the statements in Dalton's original atomic theory are still considered to be correct
today.
Ans: False
101. This figure shows a chemical reaction taking place.
Ans: True
102. An individual atom is made of smaller particles called subatomic particles.
Ans: True
103. Rutherford's alpha-scattering experiment suggested that the atom had a massive positively
charged core, which he called the nucleus.
Ans: True
104. The number of neutrons in the nucleus of an atom determines its identity.
Ans: False
105. The number of protons in the nucleus of an atom is the atomic number of that atom.
Ans: True
106. In order for an atom of an element to be neutral, its number of electrons must equal its
number of protons.
Ans: True
107. The mass number of an isotope is the sum of the number of protons and neutrons in its
nucleus.
Ans: True
108. The properties of metal ions are the same as the properties of pure metal elements.
Ans: False
109. A cation is a positively charged ion that has fewer electrons than protons.
Ans: True
110. An anion is a positively charged ion that has more electrons than protons.
Ans: False
111. One atomic mass unit is equal to the mass of a carbon-12 atom.
Ans: False
112. The relative atomic mass of an element is the average mass of its individual isotopes,
considering the relative abundance of each.
Ans: True
113. Lithium is composed of two isotopes: lithium-6 and lithium-7. Lithium-7 is the more
abundant of the two isotopes.
Ans: True
114. The mass of exactly 100 carbon atoms is 12.01 amu.
Ans: False
115. The mass of exactly 1000 magnesium atoms is 2.431  104 amu.
Ans: True
116. Mendeleev arranged his periodic table in order of increasing atomic number.
Ans: False
117. Mendeleev was able to predict the existence of unknown elements using his periodic table.
Ans: True
118. The modern periodic table is arranged in order of increasing atomic mass.
Ans: False
119. Elements within a vertical column of the periodic table are called a family or group.
Ans: True
120. A horizontal row of the periodic table is called a period.
Ans: True
121. A metalloid is an element that has physical properties similar to those of a metal, but
chemical reactivity which more closely resembles a nonmetal.
Ans: True
122. Elements in the eight groups labeled “A” are transition elements.
Ans: False
123. Elements in group IIA (2) are called alkali metals.
Ans: False
124. There are seven elements that occur naturally as diatomic molecules.
Ans: True
125. Explain what is incorrect, if anything, about the figure shown.
Ans: The reaction violates the law of conservation of mass, since there are not an equal
number of hydrogen atoms in the two images.
126. Does the figure shown represent a chemical reaction, or simply a physical change, and does
it obey the law of conservation of mass?
Ans: The figure shows a chemical reaction which obeys the law of conservation of mass.
127. Draw a nuclear model of a helium-4 atom. Label the nucleus, protons, neutrons, and
electrons, and show the appropriate number of each type of subatomic particle.
Ans:
128. What is the difference between the mass number of an atom, and its mass in amu?
Ans: The mass number is an integer, which is the sum of the protons and the neutrons in the
atom, while the mass in amu is an actual measure of the mass of an atom, often to five
or more significant figures.
129. The element fluffium (Fl) was discovered on a planet in a galaxy far, far away. Given the
information below, calculate the relative atomic mass of fluffium.
Isotope
Mass (amu)
Natural Abundance (%)
301
Fl
300.991
67.45
303
Fl
302.985
32.55
Ans: 301.6 amu
130. A new element, grubium (Gr), was discovered ground into a child's clothes. Given the
information below, calculate the relative atomic mass of grubium.
Isotope
Mass (amu)
Natural Abundance (%)
54
Gr
53.992
26.46
56
Gr
55.989
73.54
Ans: 55.46 amu
131. List several unique features of the elements in group VIIIA (18) of the periodic table.
Ans: They are all gases, they don't normally combine with other elements or exist as
diatomic molecules, and they do not form ions.
132. Describe how you would predict the charge on the ion that would be formed by a
representative element.
Ans: Representative metals will lose enough electrons to have the same number of
electrons as the noble gas that comes before them in the periodic table, while
nonmetals will gain a sufficient quantity of electrons to “catch up” to the noble gas
that follows them in the periodic table.
133. When dry ice (solid carbon dioxide) is removed from the freezer, it will sublime, or go
directly from the solid phase to the gas phase. Explain why this is not a violation of the law
of conservation of mass.
Ans: If you could capture the carbon dioxide gas and weigh it, the mass of the gas would be
the same as the mass of the dry ice you started with.
134. Two balloons are filled to equal volumes with the same number of atoms. One balloon is
filled with helium, while the other contains xenon. Without breathing in the contents of
either balloon, describe how you could tell the difference between the two balloons, and
why they would behave differently.
Ans: The helium-filled balloon would float, since helium is less dense than air, due to its
low relative atomic mass. The relative atomic mass of xenon is much greater than that
of the nitrogen and oxygen that comprise air, so it would be denser than air, and
therefore would not float.