Question 1

How many Cu atoms are present in a 75.0 cm length of 20-gauge copper wire? A 20-gauge wire has a diameter of 0.03196 in. Copper's density is 8.92 g/cm3.

Accepted Answer

A)   1.31 × 1021
B)   3.28 × 1022
C)   8.08 × 1021
D)   1.04 × 1022
E)   2.08 × 1022

Question 2

Dalton's atomic theory is based on several assumptions, which are listed below. Which of these assumptions is strictly correct? I)  All atoms of the same element are identical.
II)  Atoms are indivisible and unchangeable.
III)  Chemical changes are the result of the combination, separation, and rearrangement of atoms.

Accepted Answer

A)   I, II, and III are correct.
B)   I and III are correct.
C)   II and III are correct.
D)   I and II are correct.
E)   III is correct.

Question 3

Which of the following is a correct feature of the nuclear atom proposed by Rutherford?

Accepted Answer

A)   All atoms of an element have the same mass.
B)   The atom is mostly empty space.
C)   The number of neutrons and electrons in the atom are equal.
D)   The majority of alpha particles to strike the foil "bounced back."
E)   It is like the "plum pudding" model.

Question 4

Choose the INCORRECT statement from those given below.

Accepted Answer

A)   Atoms retain their identity during a chemical reaction.
B)   All matter is composed of atoms.
C)   Atoms combine in small, whole-numbered ratios.
D)   All atoms of a given element are identical.
E)   Different ratios of atoms produce different compounds.

Question 5

A certain element contains eleven atoms of mass 95.952 u for every four atoms of mass 98.949 u. Compute the average atomic weight of this element.

Accepted Answer

A)   97.451 u
B)   96.754 u
C)   98.150 u
D)   105.16 u
E)   96.952 u

Question 6

Which of the following statements is true concerning the masses of individual Cl atoms?

Accepted Answer

A)   All atoms have a mass of 35.45 u.
B)   Most of the atoms have a mass of 35.45 u.
C)   Some of the atoms have a mass of 35.45 u.
D)   None of the atoms have a mass of 35.45 u.
E)   All atoms have a mass of 17 u.

Question 7

Copper occurs in an isotopic mixture of 69.09% 63Cu (mass = 62.93 u per atom)  and 30.91% 65Cu (mass = 64.93 u per atom) . What is the average atomic mass of copper?

Accepted Answer

A)   64.00 u
B)   63.55 u
C)   63.45 u
D)   64.31 u
E)   29.00 u

Question 8

When decomposed chemically, 73.0 grams of a sample of HCl produce 71.0 g of Cl2 and 2.0 g of H2, while 34.0 g of a sample of H2S produce 32.0 g of S and 2.0 g of H2. This is an example of the Law:

Accepted Answer

A)   of Conservation of Mass
B)   of Multiple Proportions
C)   of Definite Proportions
D)   E = mc2
E)   of Simple Whole Numbers

Question 9

The following ratios of masses were obtained with a mass spectrometer:  /  = 1.8406,  /  = 1.5832 What is the mass of a  atom in atomic mass units?

Accepted Answer

A)   35.45 u
B)   36.36 u
C)   13.95 u
D)   35.00 u
E)   34.97 u

Question 10

Robert Millikan determined the charge on an electron.

Accepted Answer

A) True 
 B)False

Question 11

Ernest Rutherford is credited with: I)  the nuclear model of the atom
II)  the identification of alpha and beta particles
III)  the discovery of protons
IV)  the prediction of a third, neutral, subatomic particle

Accepted Answer

A)   I and II
B)   I and III
C)   I, II, III
D)   II, III, IV
E)   I, II, III, IV

Question 12

How many protons, neutrons, and electrons are in  ?

Accepted Answer

A)   12 protons, 10 electrons, 12 neutrons
B)   12 protons, 12 electrons, 12 neutrons
C)   12 protons, 12 electrons, 24 neutrons
D)   24 protons, 10 electrons, 12 neutrons
E)   10 protons, 12 electrons, 24 neutrons

Question 13

How many atoms of rubidium-85 are in 87.2 g of rubidium? Rubidium-85 is 72.2 % abundant.

Accepted Answer

A)   5.16 × 1046 atoms
B)   4.44 × 1023 atoms
C)   8.51 × 1023 atoms
D)   6.14 × 1022 atoms
E)   1.02 × 1024 atoms

Question 14

An isotope with mass number 81 has eleven more neutrons than protons. This is an isotope of what element?

Accepted Answer

A)   Tl
B)   Yb
C)   Zr
D)   Br
E)   Nb

Question 15

What is the isotopic atomic mass of an isotope if 9.7023 × 1022 atoms weighs 4.0256 g?

Accepted Answer

A)   0.64858
B)   24.305
C)   24.986
D)   13.728
E)   4.0256

Question 16

All atoms of a given element are identical.

Accepted Answer

A) True 
 B)False

Question 17

Which statement below is true?

Accepted Answer

A)   Metals gain electrons to have a positive charge.
B)   Metals gain electrons to have a negative charge.
C)   Metals lose electrons to have a positive charge.
D)   Nonmetals lose electrons.
E)   Transition metals can gain 2 or more electrons to become metal ions.

Question 18

Lead-204 has a relative abundance of 1.48%. What size block of lead (in cubic centimeters)  will contain 8.34 × 1021 atoms of lead-204? The density of lead is 11.35 g/cm3.

Accepted Answer

A)   3.75 × 10-3
B)   0.253
C)   194
D)   17.1
E)   16.8

Question 19

How many atoms of hydrogen are present in 1.5 lb of hydrogen peroxide, which is 5.93% hydrogen? (1 lb = 454 grams)

Accepted Answer

A)   2.4 × 1025 atoms
B)   1.21 × 1025 atoms
C)   1.2 × 1025 atoms
D)   2.41 × 1025 atoms
E)   1.2 × 1020 atoms

Question 20

Which of the following would be unaffected by an electric field?

Accepted Answer

A)   alpha particles
B)   beta particles
C)   gamma rays
D)   protons
E)   electrons

Exam 2: Atoms and the Atomic Theory

Copper occurs in an isotopic mixture of 69.09% 63Cu (mass = 62.93 u per atom) and 30.91% 65Cu (mass = 64.93 u per atom) . What is the average atomic mass of copper?

Correct Answer
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The following ratios of masses were obtained with a mass spectrometer: / = 1.8406, / = 1.5832 What is the mass of a atom in atomic mass units?

Correct Answer
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How many atoms of rubidium-85 are in 87.2 g of rubidium? Rubidium-85 is 72.2 % abundant.

Correct Answer
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How many atoms of hydrogen are present in 1.5 lb of hydrogen peroxide, which is 5.93% hydrogen? (1 lb = 454 grams)

Correct Answer
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When decomposed chemically, 73.0 grams of a sample of HCl produce 71.0 g of Cl₂ and 2.0 g of H₂, while 34.0 g of a sample of H₂S produce 32.0 g of S and 2.0 g of H₂. This is an example of the Law:

Correct Answer
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Which of the following is a correct feature of the nuclear atom proposed by Rutherford?

Correct Answer
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Choose the INCORRECT statement from those given below.

Correct Answer
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Ernest Rutherford is credited with: I) the nuclear model of the atom II) the identification of alpha and beta particles III) the discovery of protons IV) the prediction of a third, neutral, subatomic particle

Correct Answer
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A certain element contains eleven atoms of mass 95.952 u for every four atoms of mass 98.949 u. Compute the average atomic weight of this element.

Correct Answer
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Lead-204 has a relative abundance of 1.48%. What size block of lead (in cubic centimeters) will contain 8.34 × 10²¹ atoms of lead-204? The density of lead is 11.35 g/cm3.

Correct Answer
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Which statement below is true?

Correct Answer
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Robert Millikan determined the charge on an electron.

Correct Answer
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What is the isotopic atomic mass of an isotope if 9.7023 × 10²² atoms weighs 4.0256 g?

Correct Answer
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An isotope with mass number 81 has eleven more neutrons than protons. This is an isotope of what element?

Correct Answer
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All atoms of a given element are identical.

Correct Answer
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Which of the following would be unaffected by an electric field?

Correct Answer
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How many protons, neutrons, and electrons are in ?

Correct Answer
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Which of the following statements is true concerning the masses of individual Cl atoms?

Correct Answer
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Correct Answer
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How many Cu atoms are present in a 75.0 cm length of 20-gauge copper wire? A 20-gauge wire has a diameter of 0.03196 in. Copper's density is 8.92 g/cm3.

Correct Answer
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Exam 2: Atoms and the Atomic Theory

Copper occurs in an isotopic mixture of 69.09% 63Cu (mass = 62.93 u per atom) and 30.91% 65Cu (mass = 64.93 u per atom) . What is the average atomic mass of copper?

Correct AnswerverifiedShow Answer

The following ratios of masses were obtained with a mass spectrometer: / = 1.8406, / = 1.5832 What is the mass of a atom in atomic mass units?

Correct AnswerverifiedShow Answer

How many atoms of rubidium-85 are in 87.2 g of rubidium? Rubidium-85 is 72.2 % abundant.

Correct AnswerverifiedShow Answer

How many atoms of hydrogen are present in 1.5 lb of hydrogen peroxide, which is 5.93% hydrogen? (1 lb = 454 grams)

Correct AnswerverifiedShow Answer

When decomposed chemically, 73.0 grams of a sample of HCl produce 71.0 g of Cl2 and 2.0 g of H2, while 34.0 g of a sample of H2S produce 32.0 g of S and 2.0 g of H2. This is an example of the Law:

Correct AnswerverifiedShow Answer

Which of the following is a correct feature of the nuclear atom proposed by Rutherford?

Correct AnswerverifiedShow Answer

Choose the INCORRECT statement from those given below.

Correct AnswerverifiedShow Answer

Ernest Rutherford is credited with: I) the nuclear model of the atom II) the identification of alpha and beta particles III) the discovery of protons IV) the prediction of a third, neutral, subatomic particle

Correct AnswerverifiedShow Answer

A certain element contains eleven atoms of mass 95.952 u for every four atoms of mass 98.949 u. Compute the average atomic weight of this element.

Correct AnswerverifiedShow Answer

Lead-204 has a relative abundance of 1.48%. What size block of lead (in cubic centimeters) will contain 8.34 × 1021 atoms of lead-204? The density of lead is 11.35 g/cm3.

Correct AnswerverifiedShow Answer

Which statement below is true?

Correct AnswerverifiedShow Answer

Robert Millikan determined the charge on an electron.

Correct AnswerverifiedShow Answer

What is the isotopic atomic mass of an isotope if 9.7023 × 1022 atoms weighs 4.0256 g?

Correct AnswerverifiedShow Answer

An isotope with mass number 81 has eleven more neutrons than protons. This is an isotope of what element?

Correct AnswerverifiedShow Answer

All atoms of a given element are identical.

Correct AnswerverifiedShow Answer

Which of the following would be unaffected by an electric field?

Correct AnswerverifiedShow Answer

How many protons, neutrons, and electrons are in ?

Correct AnswerverifiedShow Answer

Which of the following statements is true concerning the masses of individual Cl atoms?

Correct AnswerverifiedShow Answer

Correct AnswerverifiedShow Answer

How many Cu atoms are present in a 75.0 cm length of 20-gauge copper wire? A 20-gauge wire has a diameter of 0.03196 in. Copper's density is 8.92 g/cm3.

Correct AnswerverifiedShow Answer

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When decomposed chemically, 73.0 grams of a sample of HCl produce 71.0 g of Cl₂ and 2.0 g of H₂, while 34.0 g of a sample of H₂S produce 32.0 g of S and 2.0 g of H₂. This is an example of the Law:

Correct Answer
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Lead-204 has a relative abundance of 1.48%. What size block of lead (in cubic centimeters) will contain 8.34 × 10²¹ atoms of lead-204? The density of lead is 11.35 g/cm3.

Correct Answer
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What is the isotopic atomic mass of an isotope if 9.7023 × 10²² atoms weighs 4.0256 g?

Correct Answer
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