Foundations of College Chemistry 14th Edition Hein - Test Bank

Foundations of College Chemistry 14th Edition Hein – Test Bank

 

Instant Download – Complete Test Bank With Answers

 

 

Sample Questions Are Posted Below

 

Package Title: Hein 14e Test Bank

Course Title: Hein 14e

Chapter Number: 5

 

 

Question type: Multiple Choice

 

 

1) Which is not part of Dalton’s atomic model?

 

1. a) Elements are composed of minute, indivisible particles called atoms.
2. b) Atoms of the same element are alike in mass.
3. c) Atoms of the same element can be different in size.
4. d) Chemical compounds are composed of two or more atoms of different elements.

 

Answer: C

 

Difficulty: easy

Learning Objective 1: Describe Dalton’s model of the atom and compare it to the earlier concepts of matter.

Section Reference 1: Section 5.1

 

 

2) Atoms are characterized by their ___.

 

1. a) mass number
2. b) atomic number
3. c) number of their neutrons
4. d) mass composition

 

Answer: B

 

Difficulty: easy

Learning Objective 1: Explain how the nuclear model of the atom differs from Dalton’s and Thomson’s model.

Section Reference 1: Section 5.4

 

 

3) What is the charge associated with a neutron?

 

1. a) +1
2. b) –1
3. c) 0
4. d) none of these choices

 

Answer: C

 

Difficulty: easy

Learning Objective 1: Use Coulomb’s Law to calculate the force between particles and distinguish between a cation and an anion

Section Reference 1: Section 5.2

 

 

4) Particles with which electric charges will attract one another?

 

1. a) positive and positive
2. b) positive and negative
3. c) negative and negative
4. d) both positive and positive and positive and negative

 

 

Answer: B

 

Difficulty: easy

Learning Objective 1: Use Coulomb’s Law to calculate the force between particles and distinguish between a cation and an anion

Section Reference 1: Section 5.2

 

 

5) Particles with which electrical charges will repel one another?

 

1. a) positive and positive
2. b) positive and negative
3. c) negative and negative
4. d) both positive and positive and negative and negative

 

Answer: D

 

Difficulty: easy

Learning Objective 1: Use Coulomb’s Law to calculate the force between particles and distinguish between a cation and an anion

Section Reference 1: Section 5.2

 

 

6) As the distance between two particles with charges that attract one another increases, the force of attraction will ___.

 

1. a) increase
2. b) decrease
3. c) remain the same

 

Answer: B

 

Difficulty: easy

Learning Objective 1: Use Coulomb’s Law to calculate the force between particles and distinguish between a cation and an anion

Section Reference 1: Section 5.2

 

 

7) As the distance between two particles with charges that repel each other increases, the force of repulsion will ___.

 

1. a) increase
2. b) decrease
3. c) remain the same

 

Answer: B

 

Difficulty: easy

Learning Objective 1: Use Coulomb’s Law to calculate the force between particles and distinguish between a cation and an anion

Section Reference 1: Section 5.2

 

 

8) What charge does a cation possess?

 

1. a) positive
2. b) negative
3. c) neutral

 

Answer: A

 

Difficulty: easy

Learning Objective 1: Use Coulomb’s Law to calculate the force between particles and distinguish between a cation and an anion

Section Reference 1: Section 5.2

 

 

9) What charge does an anion possess?

 

1. a) positive
2. b) negative
3. c) neutral

 

Answer: B

 

Difficulty: easy

Learning Objective 1: Use Coulomb’s Law to calculate the force between particles and distinguish between a cation and an anion

Section Reference 1: Section 5.2

 

 

10) What is the relative electrical charge of an electron?

 

1. a) –1
2. b) +1
3. c) –2
4. d) 0

 

Answer: A

 

Difficulty: easy

Learning Objective 1: Describe the three basic subatomic particles and how they changed Dalton’s model of the atom.

Section Reference 1: Section 5.3

 

 

11) What is the relative electrical charge of a proton?

 

1. a) –1
2. b) +1
3. c) –2
4. d) 0

 

Answer: B

 

Difficulty: easy

Learning Objective 1: Describe the three basic subatomic particles and how they changed Dalton’s model of the atom.

Section Reference 1: Section 5.3

 

 

12) Which subatomic particle(s) was (were) not part of the Thomson model of the atom?

 

1. a) proton
2. b) neutron
3. c) electron
4. d) both proton and neutron

 

Answer: B

 

Difficulty: easy

Learning Objective 1: Describe the three basic subatomic particles and how they changed Dalton’s model of the atom.

Section Reference 1: Section 5.3

 

 

13) Who is credited with demonstrating that the atom contains neutrons?

 

1. a) Rutherford
2. b) Dalton
3. c) Thomson
4. d) Chadwick

 

Answer: D

 

Difficulty: easy

Learning Objective 1: Describe the three basic subatomic particles and how they changed Dalton’s model of the atom.

Section Reference 1: Section 5.3

 

 

14) What is the relative mass of an electron?

 

1. a) 1/1837 amu
2. b) ½ amu
3. c) 1 amu
4. d) 2 amu

 

Answer: A

 

Difficulty: easy

Learning Objective 1: Describe the three basic subatomic particles and how they changed Dalton’s model of the atom.

Section Reference 1: Section 5.3

 

 

15) Which of the following pairs of subatomic particles have similar masses?

 

1. a) electrons and protons
2. b) electrons and neutrons
3. c) protons and neutrons
4. d) none of these choices

 

Answer: C

 

Difficulty: easy

Learning Objective 1: Describe the three basic subatomic particles and how they changed Dalton’s model of the atom.

Section Reference 1: Section 5.3

 

 

16) What is the relative mass of a neutron?

 

1. a) 1/1837 amu
2. b) ½ amu
3. c) 1 amu
4. d) 2 amu

 

Answer: C

 

Difficulty: easy

Learning Objective 1: Describe the three basic subatomic particles and how they changed Dalton’s model of the atom.

Section Reference 1: Section 5.3

 

 

17) The mass of a hydrogen atom is 1.673 × 10 ^–24 g. How many hydrogen atoms are present in a 1.00- g sample of hydrogen?

 

1. a) 1.00 atom
2. b) 1.67 × 10 ^–24 atoms
3. c) 5.98 × 10 ²³ atoms
4. d) 1.67 × 10 ²⁴ atoms

 

Answer: C

 

Difficulty: easy

Learning Objective 1: Explain the relationship between the atomic mass of an element and the masses of its isotopes.

Section Reference 1: Section 5.6

 

 

18) The mass of a copper atom is 1.045 × 10 ^-22 g. How many copper atoms are present in a 94.5 g sample of copper?

 

9. a) 9.04 × 10 ²³
10. b) 1.045 × 10 ^-22
11. c) 1870
12. d) 94.5

 

Answer: A

 

Difficulty: easy

Learning Objective 1: Explain the relationship between the atomic mass of an element and the masses of its isotopes.

Section Reference 1: Section 5.6

 

 

19) The nucleus of an atom usually contains ___.

 

1. a) protons
2. b) neutrons
3. c) protons and neutrons
4. c) neither protons nor neutrons

 

Answer: C

 

Difficulty: easy

Learning Objective 1: Explain how the nuclear model of the atom differs from Dalton’s and Thomson’s model.

Section Reference 1: Section 5.4

 

 

20) The mass of an atom is primarily determined by the mass of its ___.

 

1. a) protons
2. b) neutrons
3. c) protons and neutrons
4. d) neither protons nor neutrons

 

Answer: C

 

Difficulty: easy

Learning Objective 1: Explain how the nuclear model of the atom differs from Dalton’s and Thomson’s model.

Section Reference 1: Section 5.4

 

 

21) Which subatomic particle contributes least to the mass of an atom?

 

1. a) proton
2. b) neutron
3. c) electron

 

Answer: C

 

Difficulty: easy

Learning Objective 1: Describe the three basic subatomic particles and how they changed Dalton’s model of the atom.

Section Reference 1: Section 5.3

 

 

22) What subatomic particles contribute to the charge of the atom?

 

1. a) proton and neutron
2. b) neutron and electron
3. c) electron and proton
4. d) proton, electron, and neutron

 

Answer: C

 

Difficulty: easy

Learning Objective 1: Describe the three basic subatomic particles and how they changed Dalton’s model of the atom.

Section Reference 1: Section 5.3

 

 

23) Which subatomic particle is not found in the nucleus of the atom?

 

1. a) proton
2. b) neutron
3. c) electron

 

Answer: C

 

Difficulty: easy

Learning Objective 1: Explain how the nuclear model of the atom differs from Dalton’s and Thomson’s model.

Section Reference 1: Section 5.4

 

 

24) Which particle contributes the most to the electrical charge of the nucleus?

 

1. a) proton
2. b) neutron
3. c) electron

 

Answer: A

 

Difficulty: easy

Learning Objective 1: Explain how the nuclear model of the atom differs from Dalton’s and Thomson’s model.

Section Reference 1: Section 5.4

 

 

25) The electrical charge of an atom is ___.

 

1. a) positive
2. b) negative
3. c) the atom has no charge, it is neutral

 

Answer: C

 

Difficulty: easy

Learning Objective 1: Explain how the nuclear model of the atom differs from Dalton’s and Thomson’s model.

Section Reference 1: Section 5.4

 

 

26) The electrical charge of a nucleus is ___.

 

1. a) positive
2. b) negative
3. c) the nucleus has no charge, it is neutral

 

Answer: A

 

Difficulty: easy

Learning Objective 1: Explain how the nuclear model of the atom differs from Dalton’s and Thomson’s model.

Section Reference 1: Section 5.4

 

 

27) The number of protons in an atom is known as its ___.

 

1. a) atomic mass
2. b) atomic number
3. c) mass number
4. d) molecular mass

 

Answer: B

 

Difficulty: easy

Learning Objective 1: Explain how the nuclear model of the atom differs from Dalton’s and Thomson’s model.

Section Reference 1: Section 5.4

 

 

28) Different isotopes of an element are atoms of that element which have

 

1. a) the same atomic number and the same mass number.
2. b) the same atomic number and different mass number.
3. c) different atomic number and the same mass number.
4. d) different atomic number and different mass number.

 

Answer: B

 

Difficulty: easy

Learning Objective 1: Define the terms atomic number, mass number and isotope.

Section Reference 1: Section 5.5

 

 

29) Atoms of isotopes of an element contain different numbers of ___.

 

1. a) protons
2. b) neutrons
3. c) electrons

 

Answer: B

 

Difficulty: easy

Learning Objective 1: Define the terms atomic number, mass number and isotope.

Section Reference 1: Section 5.5

 

 

30) Atoms of isotopes of an element contain the same number of ___.

 

1. a) protons
2. b) neutrons
3. c) alpha particles

 

Answer: A

 

Difficulty: easy

Learning Objective 1: Define the terms atomic number, mass number and isotope.

Section Reference 1: Section 5.5

 

 

31) Mass number refers to

 

1. a) number of protons and electrons in an atom
2. b) number of neutrons and electrons in an atom
3. c) number of protons in an atom
4. d) number of protons and neutrons in an atom

 

Answer: D

 

Difficulty: easy

Learning Objective 1: Define the terms atomic number, mass number and isotope.

Section Reference 1: Section 5.5

 

 

32) In isotopic notation atomic number is represented by the subscript ___.

 

1. a) A
2. b) N
3. c) P
4. d) Z

 

Answer: D

 

Difficulty: easy

Learning Objective 1: Define the terms atomic number, mass number and isotope.

Section Reference 1: Section 5.5

 

 

33) Which of the following is not accounted for by Dalton’s theory?

 

1. a) Elements are composed of atoms.
2. b) Atoms are composed of electrons, neutrons, and protons.
3. c) Atoms combine to form compounds.
4. d) Atoms of a given element are alike in mass and size.

 

Answer: B

 

Difficulty: easy

Learning Objective 1: Describe Dalton’s model of the atom and compare it to the earlier concepts of matter.

Section Reference 1: Section 5.1

 

 

34) One isotope of oxygen has the atomic number 8 and the mass number 18. An atom of this isotope contains

 

1. a) 8 neutrons.
2. b) 10 electrons.
3. c) 8 protons.
4. d) 18 electrons.

 

Answer: C

 

Difficulty: easy

Learning Objective 1: Define the terms atomic number, mass number and isotope.

Section Reference 1: Section 5.5

 

 

35) One isotope of carbon has the atomic number 6 and the mass number 14. An atom of this isotope contains

 

1. a) 8 protons.
2. b) 14 neutrons.
3. c) 6 neutrons.
4. d) 6 electrons.

 

Answer: D

 

Difficulty: easy

Learning Objective 1: Define the terms atomic number, mass number and isotope.

Section Reference 1: Section 5.5

 

 

36) An isotope of sodium has the atomic number 11 and the mass number 23. An atom of this isotope contains

 

1. a) 12 electrons.
2. b) 12 protons.
3. c) 12 neutrons.
4. d) 23 electrons.

 

Answer: C

 

Difficulty: easy

Learning Objective 1: Define the terms atomic number, mass number and isotope.

Section Reference 1: Section 5.5

 

 

37) Naturally occurring neon exists as three isotopes. 90.51% is Ne-20 with a mass of 19.99 amu, 0.27% is Ne-21 with a mass of 20.99 amu, and 9.22% is Ne-22 with a mass of 21.99 amu. What is the atomic mass of neon?

 

10. a) 10.00 amu
11. b) 20.18 amu
12. c) 20.99 amu
13. d) 62.97 amu

 

Answer: B

 

Difficulty: medium

Learning Objective 1: Explain the relationship between the atomic mass of an element and the masses of its isotopes.

Section Reference 1: Section 5.6

 

 

38) Naturally occurring silicon exists as three isotopes. 92.23% is Si-28 with a mass of 27.977 amu, 4.67% is Si- 29 with a mass of 28.977 amu, and 3.10% is Si-30 with a mass of 29.974 amu. What is the atomic mass of silicon?

 

14. a) 14.00 amu
15. b) 28.09 amu
16. c) 28.98 amu
17. d) 86.93 amu

 

Answer: B

 

Difficulty: medium

Learning Objective 1: Explain the relationship between the atomic mass of an element and the masses of its isotopes.

Section Reference 1: Section 5.6

 

 

39) What is the mass number of an atom that contains 9 protons, 9 electrons, and 10 neutrons?

 

1. a) 9
2. c) 10
3. c) 18
4. d) 19

 

Answer: D

 

Difficulty: easy

Learning Objective 1: Define the terms atomic number, mass number and isotope.

Section Reference 1: Section 5.5

 

 

40) What is the atomic number of an atom that contains 40 protons, 40 electrons, and 51 neutrons?

 

1. a) 11
2. b) 40
3. c) 51
4. d) 91

 

Answer: B

 

Difficulty: easy

Learning Objective 1: Define the terms atomic number, mass number and isotope.

Section Reference 1: Section 5.5

 

 

41) What is the mass number of an atom that contains 30 protons, 30 electrons, and 35 neutrons?

 

1. a) 5
2. b) 30
3. c) 65
4. d) 95

 

Answer: C

 

Difficulty: easy

Learning Objective 1: Define the terms atomic number, mass number and isotope.

Section Reference 1: Section 5.5

 

 

42) What is the mass number of an atom that contains 23 protons, 23 electrons, and 28 neutrons?

 

1. a) 5
2. b) 28
3. c) 51
4. d) 74

 

Answer: C

 

Difficulty: easy

Learning Objective 1: Define the terms atomic number, mass number and isotope.

Section Reference 1: Section 5.5

 

 

43) What is the atomic number of magnesium?

 

1. a) 12
2. b) 24
3. c) 25
4. d) 55

 

Answer: A

 

Difficulty: easy

Learning Objective 1: Define the terms atomic number, mass number and isotope.

Section Reference 1: Section 5.5

 

 

44) An isotope of sodium has a mass number of 23. What is the number of neutrons for this isotope?

 

1. a) 23
2. b) 34
3. c) 12
4. d) none of these choices

 

Answer: C

 

Difficulty: easy

Learning Objective 1: Define the terms atomic number, mass number and isotope.

Section Reference 1: Section 5.5

 

 

45) The element with atomic number 27 is ___.

 

1. a) carbon
2. b) copper
3. c) cobalt
4. d) calcium

 

Answer: C

 

Difficulty: easy

Learning Objective 1: Define the terms atomic number, mass number and isotope.

Section Reference 1: Section 5.5

 

 

46) The element with the atomic number 19

 

1. a) is a member of alkali metals.
2. b) is shiny and good conductor of heat.
3. c) is highly reactive.
4. d) All of these answer choices are correct.

 

Answer: D

 

Difficulty: easy

Learning Objective 1: Define the terms atomic number, mass number and isotope.

Section Reference 1: Section 5.5

 

 

47) The element with atomic number 53 is ___.

 

1. a) iron
2. b) iridium
3. c) iodine
4. d) indium

 

Answer: C

 

Difficulty: easy

Learning Objective 1: Explain how the nuclear model of the atom differs from Dalton’s and Thomson’s model.

Section Reference 1: Section 5.4

 

 

48) Models of the atom were proposed by Rutherford, Dalton, and Thomson. Which choice places them in the correct chronological order of their appearance?

 

1. a) Rutherford, Dalton, Thomson
2. b) Thomson, Rutherford, Dalton
3. c) Dalton, Rutherford, Thomson
4. d) Dalton, Thomson, Rutherford

 

Answer: D

 

Difficulty: easy

Learning Objective 1: Explain how the nuclear model of the atom differs from Dalton’s and Thomson’s model.

Section Reference 1: Section 5.4

 

 

49) How many electrons are in a neutral atom of Ar-40?

 

1. a) 18
2. b) 22
3. c) 40
4. d) 58

 

Answer: A

 

Difficulty: easy

Learning Objective 1: Define the terms atomic number, mass number and isotope.

Section Reference 1: Section 5.5

 

 

50) How many protons are in a neutral atom of Ar-40?

 

1. a) 18
2. b) 22
3. c) 40
4. d) 58

 

Answer: A

 

Difficulty: easy

Learning Objective 1: Define the terms atomic number, mass number and isotope.

Section Reference 1: Section 5.5

 

 

51) What is the number of neutrons in a neutral atom of Ar-40?

 

1. a) 18
2. b) 22
3. c) 40
4. d) 58

 

Answer: B

 

Difficulty: easy

Learning Objective 1: Define the terms atomic number, mass number and isotope.

Section Reference 1: Section 5.5

 

 

52) Which contains the largest number of neutrons?

 

1. a) C-12
2. b) P-31
3. c) Br-80
4. d) Sr-90

 

Answer: D

 

Difficulty: easy

Learning Objective 1: Define the terms atomic number, mass number and isotope.

Section Reference 1: Section 5.5

 

 

53) Which contains the fewest neutrons?

 

1. a) H-2
2. b) H-3
3. c) He-4
4. d) He-5

 

Answer: A

 

Difficulty: easy

Learning Objective 1: Define the terms atomic number, mass number and isotope.

Section Reference 1: Section 5.5

 

 

54) Which isotope contains the same number of protons, neutrons, and electrons?

 

1. a) H-1
2. b) Na-23
3. c) C-12
4. d) Al-27

 

Answer: C

 

Difficulty: easy

Learning Objective 1: Define the terms atomic number, mass number and isotope.

Section Reference 1: Section 5.5

 

 

55) Which isotope has the same number of protons, neutrons, and electrons?

 

1. a) Cl-35
2. b) Cl-37
3. c) P-31
4. d) S-32

 

Answer: D

 

Difficulty: easy

Learning Objective 1: Define the terms atomic number, mass number and isotope.

Section Reference 1: Section 5.5

 

 

56) The average mass of one atom of carbon is 2.00  10 ^–23 g. How many carbon atoms are present in a 40.0 g sample of carbon?

 

7. a) 7.96 10 ^–22
8. b) 4.98 10 ^-25
9. c) 2.00 10 ²⁴
10. d) 2.06 10 ⁴

 

Answer: C

 

Difficulty: medium

Learning Objective 1: Explain the relationship between the atomic mass of an element and the masses of its isotopes.

Section Reference 1: Section 5.6

 

 

57) The average mass of an atom of sulfur is 5.33  10 ^–23 g. How many sulfur atoms are present in a 100.0 g sample of sulfur?

 

5. a) 5.33 10 ^–21
6. b) 1.88 10 ^–21
7. c) 5.33 10 ²⁴
8. d) 1.88 10 ²⁴

 

Answer: D

 

Difficulty: medium

Learning Objective 1: Explain the relationship between the atomic mass of an element and the masses of its isotopes.

Section Reference 1: Section 5.6

 

 

58) The concept that most of the atom’s mass is concentrated in a small nucleus surrounded by electrons was the contribution of ___.

 

1. a) Dalton
2. b) Thomson
3. c) Rutherford
4. d) Chadwick

 

Answer: C

 

Difficulty: easy

Learning Objective 1: Explain how the nuclear model of the atom differs from Dalton’s and Thomson’s model.

Section Reference 1: Section 5.4

 

 

59) The number of protons and neutrons in an atom are added to find the atom’s

 

1. a) atomic number.
2. b) ionic charge.
3. c) number of electrons.
4. d) mass number.

 

Answer: D

 

Difficulty: easy

Learning Objective 1: Define the terms atomic number, mass number and isotope.

Section Reference 1: Section 5.5

 

 

60) An isotope has 13 protons, 14 neutrons, and 13 electrons. Which of the following is the isotope?

 

1. a) Al-13
2. b) Al-14
3. c) Al-27
4. d) Al-40

 

Answer: C

 

Difficulty: easy

Learning Objective 1: Define the terms atomic number, mass number and isotope.

Section Reference 1: Section 5.5

 

 

61) An isotope has 15 protons, 16 neutrons, and 15 electrons. Which of the following is the isotope?

 

1. a) P-30
2. b) P-31
3. c) S-30
4. d) S-31

 

Answer: B

 

Difficulty: easy

Learning Objective 1: Define the terms atomic number, mass number and isotope.

Section Reference 1: Section 5.5

 

 

62) The number of protons in an atom of sodium-23 is ___.

 

1. a) 11
2. b) 12
3. c) 16
4. d) 23

 

Answer: A

 

Difficulty: easy

Learning Objective 1: Define the terms atomic number, mass number and isotope.

Section Reference 1: Section 5.5

 

 

63) The number of protons in an atom of boron-11 is ___.

 

1. a) 4
2. b) 5
3. c) 6
4. d) 7

 

Answer: B

 

Difficulty: easy

Learning Objective 1: Define the terms atomic number, mass number and isotope.

Section Reference 1: Section 5.5

 

 

64) Isotopes of an element always have the same

 

1. a) mass number.
2. b) number of neutrons.
3. c) number of subatomic particles.
4. d) atomic number.

 

Answer: D

 

Difficulty: easy

Learning Objective 1: Define the terms atomic number, mass number and isotope.

Section Reference 1: Section 5.5

 

 

65) The element with atomic number 53 always contains

 

1. a) 53 neutrons.
2. b) 53 protons.
3. c) 26 neutrons and 27 protons.
4. d) 26 protons and 27 neutrons.

 

Answer: B

 

Difficulty: easy

Learning Objective 1: Define the terms atomic number, mass number and isotope.

Section Reference 1: Section 5.5

 

 

66) Atom A has 5 protons and 6 neutrons; atom B has 6 protons and 5 neutrons. These atoms are

 

1. a) isotopes of the same element.
2. b) isomers of the same element.
3. c) atoms of different elements.
4. d) identical in physical properties.

 

Answer: C

 

Difficulty: easy

Learning Objective 1: Define the terms atomic number, mass number and isotope.

Section Reference 1: Section 5.5

 

 

67) The number of electrons in an atom of phosphorous-31 is ___.

 

1. a) 9
2. b) 15
3. c) 16
4. d) 22

 

Answer: B

 

Difficulty: easy

Learning Objective 1: Define the terms atomic number, mass number and isotope.

Section Reference 1: Section 5.5

 

 

68) The number of neutrons in an atom of hydrogen-1 is ___.

 

1. a) 1
2. b) 2
3. c) 3
4. d) 0

 

Answer: D

 

Difficulty: easy

Learning Objective 1: Define the terms atomic number, mass number and isotope.

Section Reference 1: Section 5.5

 

 

69) Which experiment led to the notion that the atom contains an extremely small, positively charged nucleus?

 

1. a) Becquerel’s radioactivity experiments
2. b) Rutherford’s gold foil experiment
3. c) Thomson’s cathode ray experiment
4. d) Dalton’s atomic experiment

 

Answer: B

 

Difficulty: easy

Learning Objective 1: Explain how the nuclear model of the atom differs from Dalton’s and Thomson’s model.

Section Reference 1: Section 5.4

 

 

70) Let Z represent atomic number, A represent mass number, and N represent the number of neutrons in an atom. Which of the following is correct?

 

1. a) N = A + Z
2. b) Z = A + N
3. c) N = A – Z
4. d) A = N – Z

 

Answer: C

 

Difficulty: medium

Learning Objective 1: Define the terms atomic number, mass number and isotope.

Section Reference 1: Section 5.5

 

 

71) The atomic mass of an element is

 

1. a) the mass of the most abundant isotope of that element.
2. b) the weighted average of the masses of the naturally occurring isotopes of that element.
3. c) the arithmetic average of the masses of the isotopes of that element.
4. d) the ratio of the mass of one atom of an isotope of that element to the mass of hydrogen.

 

Answer: B

 

Difficulty: easy

Learning Objective 1: Explain the relationship between the atomic mass of an element and the masses of its isotopes.

Section Reference 1: Section 5.6

 

 

72) Ca-40, K-39, and Sc-41 all have the same

 

1. a) atomic mass.
2. b) atomic number.
3. c) number of electrons.
4. d) number of neutrons.

 

Answer: D

 

Difficulty: easy

Learning Objective 1: Define the terms atomic number, mass number and isotope.

Section Reference 1: Section 5.5

 

 

73) The name of the isotope containing one proton and two neutrons is ___.

 

1. a) protium
2. b) deuterium
3. c) tritium
4. d) helium

 

Answer: C

 

Difficulty: easy

Learning Objective 1: Define the terms atomic number, mass number and isotope.

Section Reference 1: Section 5.5

 

 

74) Which of the following is not supported by Dalton’s atomic theory?

 

1. a) atoms
2. b) isotopes
3. c) compounds
4. d) elements

 

Answer: B

 

Difficulty: easy

Learning Objective 1: Describe Dalton’s model of the atom and compare it to the earlier concepts of matter.

Section Reference 1: Section 5.1

 

 

75) Based on the following information, calculate the mass of one atom of .
mass of an electron = 9.110 × 10^–28 g

mass of a proton = 1.673 × 10^–24 g

mass of a neutron = 1.675 × 10^–24 g

 

58. a) 58.69 g
59. b) 1.474 × 10^–22 g
60. c) 9.746 × 10^–23 g
61. d) 1.005 × 10^–-22 g

 

Answer: D

 

Difficulty: hard

Learning Objective 1: Define the terms atomic number, mass number and isotope.

Section Reference 1: Section 5.5

 

 

76) Based on the following information, calculate the mass of one atom of .
mass of an electron = 9.110 × 10^–28 g

mass of a proton = 1.673 × 10^–24 g

mass of a neutron = 1.675 × 10^–24 g

 

1. a) 1.440 × 10^–22 g
2. b) 87.62 g
3. c) 2.077 × 10^–22 g
4. d) 1.455 × 10^–22 g

 

Answer: A

 

Difficulty: hard

Learning Objective 1: Define the terms atomic number, mass number and isotope.

Section Reference 1: Section 5.5

 

 

77) Ions can be formed from atoms by losing or gaining electrons. Select the alternative that states the correct number of protons, neutrons, and electrons in .

 

1. a) 13 protons, 14 neutrons, and 16 electrons
2. b) 13 protons, 14 neutrons, and 10 electrons
3. c) 10 protons, 17 neutrons, 13 electrons
4. d) 13 protons, 27 neutrons, 10 electrons

 

Answer: B

 

Difficulty: hard

Learning Objective 1: Define the terms atomic number, mass number and isotope.

Section Reference 1: Section 5.5

 

 

78) Ions can be formed from atoms by losing or gaining electrons. Select the alternative that states the correct number of protons, neutrons, and electrons in .

 

1. a) 29 protons, 34 neutrons, 31 electrons
2. b) 29 protons, 34 neutrons, 27 electrons
3. c) 27 protons, 29 neutrons, 29 electrons
4. d) 29 protons, 63 neutrons, 29 electrons

 

Answer: B

 

Difficulty: hard

Learning Objective 1: Define the terms atomic number, mass number and isotope.

Section Reference 1: Section 5.5

 

 

79) Ions can be formed from atoms by losing or gaining electrons. Select the alternative that states the correct number of protons, neutrons, and electrons in .

 

1. a) 17 protons, 18 neutrons, 16 electrons
2. b) 17 protons, 18 neutrons, 18 electrons
3. c) 18 protons, 17 neutrons, 19 electrons
4. d) 17 protons, 36 neutrons, 17 electrons

 

Answer: B

 

Difficulty: hard

Learning Objective 1: Define the terms atomic number, mass number and isotope.

Section Reference 1: Section 5.5

 

 

80) Sulfur occurs naturally as four isotopes: ³²S with a mass of 31.9721 amu, ³³S with a mass of 32.9715 amu, ³⁴S 33.9679 amu, and ³⁶S with a mass of 35.9671 amu. Based on the information that is given on the periodic table, which isotope is the most abundant?

 

1. a) ³²S
2. b) ³³S
3. c) ³⁴S
4. d) ³⁶S

 

Answer: A

 

Difficulty: hard

Learning Objective 1: Explain the relationship between the atomic mass of an element and the masses of its isotopes.

Section Reference 1: Section 5.6

 

 

81) Chromium occurs naturally as four isotopes: ⁵⁰Cr with a mass of 49.9460 amu, ⁵²Cr with a mass of 51.9405 amu, ⁵³Cr with a mass of 52.9407 amu, and ⁵⁴Cr with a mass of 53.9389 amu. Based on the information that is given on the periodic table, which isotope is the most abundant?

 

1. a) ⁵⁰Cr
2. b) ⁵²Cr
3. c) ⁵³Cr
4. d) ⁵⁴Cr

 

Answer: B

 

Difficulty: hard

Learning Objective 1: Explain the relationship between the atomic mass of an element and the masses of its isotopes.

Section Reference 1: Section 5.6

 

 

82) Which of the following pairs of hypothetical atoms are isotopes?

 

1. a) and
2. b) and
3. c) and
4. d) and

 

Answer: C

 

Difficulty: medium

Learning Objective 1: Define the terms atomic number, mass number and isotope.

Section Reference 1: Section 5.5

 

 

83) An atom of zinc has a mass of 65.39 amu. One of its isotopes has an 18.75% abundance. Since 1 amu = 1.6606 × 10^–24 g, how many of atoms of this zinc isotope would be present in a 1.00 g sample of zinc?

 

9. a) 9.209 × 10²¹ atoms
10. b) 4.911 × 10²² atoms
11. c) 1.727 × 10²¹ atoms
12. d) 4.762 × 10²¹ atoms

 

Answer: C

 

Difficulty: hard

Learning Objective 1: Explain the relationship between the atomic mass of an element and the masses of its isotopes.

Section Reference 1: Section 5.6

 

 

84) An atom of gallium has a mass of 69.72 amu. One of its isotopes, , has a 39.89% abundance. Since 1 amu = 1.6606 × 10^–24 g, how many atoms of this gallium isotope would be present in a 1.00 mg sample of gallium?

 

3. a) 3.445 × 10¹⁸ atoms
4. b) 8.637 × 10¹⁸ atoms
5. c) 2.165 × 10¹⁹ atoms
6. d) 9.501 × 10¹⁸ atoms

 

Answer: A

 

Difficulty: hard

Learning Objective 1: Explain the relationship between the atomic mass of an element and the masses of its isotopes.

Section Reference 1: Section 5.6

 

 

85) The two naturally occurring isotopes of boron, boron-10 and boron-11 have masses of 10.01 g and 11.30 amu. What is the percent abundance of the isotope with the mass of 11.0093 amu? (atomic mass of boron is 10.81amu)

 

1. a) 11%
2. b) 38%
3. c) 62%
4. d) 91%

 

Answer: C

 

Difficulty: hard

Learning Objective 1: Explain the relationship between the atomic mass of an element and the masses of its isotopes.

Section Reference 1: Section 5.6

 

 

86) An ion that consists of 24 protons, 30 neutrons, and 22 electrons has

 

1. a) gained six electrons.
2. b) lost eight electrons.
3. c) gained two electrons.
4. d) lost two electrons.

 

Answer: D

 

Difficulty: medium

Learning Objective 1: Define the terms atomic number, mass number and isotope.

Section Reference 1: Section 5.5

 

 

87) An ion that consists of 33 protons, 42 neutrons, and 36 electrons has

 

1. a) gained three electrons.
2. b) lost three electrons.
3. c) gained six electrons.
4. d) lost nine electrons.

 

Answer: A

 

Difficulty: medium

Learning Objective 1: Define the terms atomic number, mass number and isotope.

Section Reference 1: Section 5.5

 

 

88) Select the hypothetical atom that could be an isotope of Ru-102.

 

a)

b)

c)

d)

 

Answer: A

 

Difficulty: medium

Learning Objective 1: Define the terms atomic number, mass number and isotope.

Section Reference 1: Section 5.5

 

 

Question type: True/False

 

 

89) Dalton’s atomic model states that all atoms are composed of protons, neutrons, and electrons.

 

Answer: False

 

Difficulty: easy

Learning Objective 1: Describe Dalton’s model of the atom and compare it to the earlier concepts of matter.

Section Reference 1: Section 5.1

 

 

90) The atomic number of an atom is equal to its number of protons.

 

Answer: True

 

Difficulty: easy

Learning Objective 1: Explain how the nuclear model of the atom differs from Dalton’s and Thomson’s model.

Section Reference 1: Section 5.4

 

 

91) The mass number of an atom is the sum of its protons plus electrons.

 

Answer: False

 

Difficulty: easy

Learning Objective 1: Define the terms atomic number, mass number and isotope.

Section Reference 1: Section 5.5

 

 

92) An atom of silver-108 contains 47 protons, 47 electrons, and 61 neutrons.

 

Answer: True

 

Difficulty: easy

Learning Objective 1: Define the terms atomic number, mass number and isotope.

Section Reference 1: Section 5.5

 

 

93) Protons and neutrons have exactly the same masses.

 

Answer: False

 

Difficulty: easy

Learning Objective 1: Describe the three basic subatomic particles and how they changed Dalton’s model of the atom.

Section Reference 1: Section 5.3

 

 

94) Cations are electrically negative and anions are electrically positive.

 

Answer: False

 

Difficulty: easy

Learning Objective 1: Use Coulomb’s Law to calculate the force between particles and distinguish between a cation and an anion.

Section Reference 1: Section 5.2

 

 

95) The majority of the volume of an atom is empty space.

 

Answer: True

 

Difficulty: easy

Learning Objective 1: Explain how the nuclear model of the atom differs from Dalton’s and Thomson’s model.

Section Reference 1: Section 5.4

 

 

96) The majority of the mass of an atom is contained in a very small, very dense, positively charged region.

 

Answer: True

 

Difficulty: easy

Learning Objective 1: Explain how the nuclear model of the atom differs from Dalton’s and Thomson’s model.

Section Reference 1: Section 5.4

 

 

97) The three isotopes of hydrogen are protium, deuterium, and tritium.

 

Answer: True

 

Difficulty: easy

Learning Objective 1: Define the terms atomic number, mass number and isotope.

Section Reference 1: Section 5.5

 

 

98) One atomic mass unit is 1/12 the mass of an atom of carbon-12.

 

Answer: True

 

Difficulty: easy

Learning Objective 1: Explain the relationship between the atomic mass of an element and the masses of its isotopes.

Section Reference 1: Section 5.6

 

 

99) The neutron has a charge of negative one.

 

Answer: False

 

Difficulty: easy

Learning Objective 1: Describe the three basic subatomic particles and how they changed Dalton’s model of the atom.

Section Reference 1: Section 5.3

 

 

100) Rutherford’s gold foil experiment proved that the volume of the atom is mostly empty space.

 

Answer: True

 

Difficulty: easy

Learning Objective 1: Explain how the nuclear model of the atom differs from Dalton’s and Thomson’s model.

Section Reference 1: Section 5.4

 

 

Question type: Essay

 

 

101) Explain why the atomic masses of elements are not whole numbers.

 

Answer:

 

Difficulty: medium

Learning Objective 1: Explain the relationship between the atomic mass of an element and the masses of its isotopes.

Section Reference 1: Section 5.6

Solution: Atomic masses are not whole numbers because they are weighted averages of the masses of the naturally occurring isotopes of an element. While an average could be a whole number, usually it is not.

 

 

102) Compare and contrast the mass, electrical charge, and location of the three major subatomic particles.

 

Answer:

 

Difficulty: easy

Learning Objective 1: Describe the three basic subatomic particles and how they changed Dalton’s model of the atom.

Learning Objective 2: Explain how the nuclear model of the atom differs from Dalton’s and Thomson’s model.

Section Reference 1: Sections 5.3 and 5.4

Solution: The proton has a mass of one amu, a charge of positive one, and is located in the nucleus of the atom. The neutron has a mass of one amu, no electrical charge, and is located in the nucleus of the atom. The electron has a mass of 1/1837 amu, a charge of negative one, and is located outside the nucleus of the atom.

 

 

103) What is meant by the terms atom and ion? How are they alike and how are they different? Give examples.

 

Answer:

 

Difficulty: medium

Learning Objective 1: Describe the three basic subatomic particles and how they changed Dalton’s model of the atom.

Learning Objective 2: Explain how the nuclear model of the atom differs from Dalton’s and Thomson’s model.

Section Reference 1: Section 5.3 and 5.4

Solution: An atom is the smallest neutral particle of an element that can enter into a chemical reaction. Atoms are composed of protons, neutrons and electrons. In atoms the number of protons always equals the number of electrons. Atoms are always electrically neutral. An ion is a positively or negatively charged particle, consisting of one or more atoms, which has either gained or lost electrons. If it gains electrons it acquires a negative charge and if it loses electrons it acquires a positive charge.

 

 

104) How are the different isotopes of an element alike; how are they different?

 

Answer:

 

Difficulty: easy

Learning Objective 1: Define the terms atomic number, mass number and isotope.

Section Reference 1: Section 5.5

Solution: All isotopes of an element always have the same number of protons or atomic number. The difference between various isotopes of an element is that they have different numbers of neutrons and different mass numbers.

 

 

105) The nucleus of a C-12 atom has a radius of 2.7 × 10 ^–15 m. An atom of C-12 has a radius of 7.7 × 10 ^–11 m. The volume of a sphere can be calculated using the formula . Assume that both the nucleus and the atom are spherical in shape and that p = 3.1416. a) Calculate the volume of a C-12 nucleus. b) Calculate the volume of a C-12 atom. c) How many times larger is the volume of a C-12 atom than that of its nucleus?

 

Answer:

 

Difficulty: hard

Learning Objective 1: Explain how the nuclear model of the atom differs from Dalton’s and Thomson’s model.

Section Reference 1: Section 5.4

Solution: a) 8.2 10 ^–44 m³; b) 1.9  10 ^–30 m ³; c) 2.3 10 ¹³ times

 

 

106) The nucleus of an Ar-40 atom has a radius of 4.1 × 10 ^–15 m. An atom of Ar-40 has a radius of 9.4 × 10^–11 m. The volume of a sphere can be calculated using the formula . Assume that both the nucleus and the atom are spherical in shape and that p = 3.1416. a) Calculate the volume of an Ar-40 nucleus. b) Calculate the volume of an Ar-40 atom. c) How many times larger is the volume of an Ar-40 atom than that of its nucleus?

 

Answer:

 

Difficulty: hard

Learning Objective 1: Explain how the nuclear model of the atom differs from Dalton’s and Thomson’s model.

Section Reference 1: Section 5.4

Solution: a) 2.9  10^–43 m ³; b) 3.5  10^–30 m ³; c) 1.2  10¹³ times

 

 

107) In 1911 Ernest Rutherford performed an experiment known as the “Gold Foil Experiment.” He fired a stream of positively charged alpha particles at a sheet of gold foil, which was approximately 1000 atoms thick. Alpha particles have a mass of 4 amu and a charge of +2. Almost all of the alpha particles passed straight through 1000 atoms of gold. A few particles were deflected or even bounced back from the foil. Alpha particles are more than 7000 times more massive than electrons. What can you conclude regarding the structure of the atom from these observations?

 

Answer:

 

Difficulty: medium

Learning Objective 1: Explain how the nuclear model of the atom differs from Dalton’s and Thomson’s model.

Section Reference 1: Section 5.4

Solution: The fact that most of the particles passed straight through 1000 atoms and struck nothing means that the vast majority of the volume of an atom is empty space. The alpha particle has a mass of 4 amu and a charge of +2. They would be deflected by relatively massive positively charged regions. Since only very few particles were deflected, this region would have to be very small. Since the majority of the mass of the atom is located in this very small volume, the volume would be extremely dense. As a result of these interpretations Rutherford envisioned an atom with these properties: (1) The great majority of the volume is empty space. (2) There is a very small, very dense, positively charged region within the atom. We now call this region the nucleus.

 

 

 

108) The following questions refer to an atom of the isotope ⁶⁵Cu.

1. a) What is the atomic number of this element?
   b) What is the mass number of this isotope?
   c) How many protons, neutrons, and electrons are in this atom?
   d) What is the nuclear charge of this atom?
   e) What is the overall charge of this atom?

 

Answer:

 

Difficulty: medium

Learning Objective 1: Define the terms atomic number, mass number and isotope.

Section Reference 1: Section 5.5

Solution: a) Atomic number = 29; b) Mass number = 65; c) In this atom there are 29 protons, 36 neutrons, and 29 electrons; d) The nuclear charge of this atom is +29. The overall charge of this atom is zero.

 

 

109) Explain how Rutherford’s gold foil experiment changed the model of the atom proposed by Thomson.

 

Answer:

 

Difficulty: easy

Learning Objective 1: Explain how the nuclear model of the atom differs from Dalton’s and Thomson’s model.

Section Reference 1: Section 5.4

Solution: Thomson’s model of the atom (or “plum-pudding model”), portrayed all subatomic particles scattered over the volume of the atom. Rutherford’s gold foil experiment showed instead that the protons were concentrated in a very small, dense region (the nucleus) and that most of the volume occupied by an atom is actually empty space.

 

 

110) Rubidium occurs naturally as two isotopes:  with a mass of 84.9117 amu and  with a mass of 86.9092 amu. Given that the atomic mass of rubidium is 85.47 amu, what are the natural abundances of the two isotopes?

 

Answer:

 

Difficulty: hard

Learning Objective 1: Explain the relationship between the atomic mass of an element and the masses of its isotopes.

Section Reference 1: Section 5.6

Solution:  = 72.05%;  = 27.95%

 

 

111) Define in simple terms the concept of natural abundance for the isotopes of any element and how it determines the average atomic masses of the elements.

 

Answer:

 

Difficulty: medium

Learning Objective 1: Explain the relationship between the atomic mass of an element and the masses of its isotopes.

Section Reference 1: Section 5.6

Solution: Imagine taking a random sample of 100 atoms of any element in the periodic table. The natural abundance of each isotope corresponds to how many atoms of each isotope we would have among those 100 atoms from our original sample. Because not all of the atoms from a single element are equal in everything (i.e., they may have different number of neutrons), the contribution to the average atomic mass of an element needs to be calculated from not only the masses of each of its isotopes, but also their relative contributions to the total mass based on their natural abundances.