Chapter 2 1 Which of the following is an example of the law of multiple

Chemistry: A Molecular Approach, 2e (Tro)

Chapter 2 Atoms and Elements

Multiple Choice Questions

1) In a chemical reaction, matter is neither created or destroyed. Which law does this refer to?

A) Law of Definite Proportions

B) Law of the Conservation of Mass

C) Law of Modern Atomic Theory

D) Law of Multiple Proportions

E) First Law of Thermodynamics

2) All samples of a given compound, regardless of their source or how they were prepared, have the

same proportions of their constituent elements. Which law does this refer to?

A) Law of Definite Proportions

B) Law of the Conservation of Mass

C) Law of Modern Atomic Theory

D) Law of Multiple Proportions

E) First Law of Thermodynamics

3) When two elements form two different compounds, the masses of element B that combine with 1 g of

element A can be expressed as a ratio of small whole numbers. Which law does this refer to?

A) Law of Definite Proportions

B) Law of the Conservation of Mass

C) Law of Modern Atomic Theory

D) Law of Multiple Proportions

E) First Law of Thermodynamics

4) Which of the following is an example of the law of multiple proportions?

A) A sample of chlorine is found to contain three times as much Cl-35 as Cl-37.

B) Two different compounds formed from carbon and oxygen have the following mass ratios:

1.33 g O: 1 g C and 2.66 g O: 1 g C.

C) Two different samples of table salt are found to have the same ratio of sodium to chlorine.

D) The atomic mass of bromine is found to be 79.90 amu.

E) Nitrogen dioxide always has a mass ratio of 2.28 g O: 1 g N.

5) Which of the following statements is FALSE according to Dalton’s Atomic Theory?

A) Atoms combine in simple whole number ratios to form compounds.

B) All atoms of chlorine have identical properties that distinguish them from other elements.

C) One carbon atom will combine with one oxygen atom to form a molecule of carbon monoxide.

D) Atoms of sodium do not change into another element during chemical reaction with chlorine.

E) An atom of nitrogen can be broken down into smaller particles that will still have the unique

properties of nitrogen.

6) Identify the description of an atom.

A) neutrons and electrons in nucleus; protons in orbitals

B) neutrons in nucleus; protons and electrons in orbitals

C) protons and neutrons in nucleus; electrons in orbitals

D) protons and electrons in nucleus; neutrons in orbitals

E) electrons in nucleus; protons and neutrons in orbitals

7) Identify the charges of the protons, neutrons, and electrons.

A) protons +1, neutrons 0, electrons -1

B) protons 0, neutrons -1, electrons +1

C) protons -1, neutrons 0, electrons +1

D) protons 0, neutrons +1, electrons -1

E) protons +1, neutrons -1, electrons 0

8) The mass number is equal to

A) the sum of the number of the electrons and protons.

B) the sum of the number of the neutrons and electrons.

C) the sum of the number of protons, neutrons, and electrons.

D) the sum of the number of protons and neutrons.

9) What does “X” represent in the following symbol?

X

A) mercury

B) chlorine

C) scandium

D) bromine

E) selenium

10) What does “X” represent in the following symbol?

X

A) silicon

B) sulfur

C) zinc

D) ruthenium

E) nickel

11) Determine the number of protons, neutrons and electrons in the following:

X

A) p+ = 18 n° = 18 e– = 22

B) p+ = 18 n° = 22 e– = 18

C) p+ = 22 n° = 18 e– = 18

D) p+ = 18 n° = 22 e– = 40

E) p+ = 40 n° = 22 e– = 18

12) Determine the number of protons, neutrons and electrons in the following:

X

A) p+ = 12 n° = 25 e– = 12

B) p+ = 12 n° = 12 e– = 13

C) p+ = 12 n° = 13 e– = 12

D) p+ = 25 n° = 12 e– = 13

E) p+ = 12 n° = 13 e– = 25

13) Determine the number of protons, neutrons and electrons in the following:

X

A) p+ = 36 n° = 29 e– = 36

B) p+ = 29 n° = 29 e– = 36

C) p+ = 36 n° = 36 e– = 29

D) p+ = 29 n° = 36 e– = 29

E) p+ = 29 n° = 36 e– = 36

14) What element is defined by the following information?

p+ = 11 n° = 12 e– = 11

A) sodium

B) vanadium

C) magnesium

D) titanium

15) What element is defined by the following information?

p+ = 20 n° = 20 e– = 20

A) zirconium

B) calcium

C) potassium

D) neon

E) argon

16) What element is defined by the following information?

p+ = 17 n° = 20 e– = 17

A) calcium

B) rubidium

C) chlorine

D) neon

E) oxygen

17) Which of the following statements about subatomic particles is TRUE?

A) A neutral atom contains the same number of protons and electrons.

B) Protons have about the same mass as electrons.

C) Electrons make up most of the mass of an atom.

D) Protons and neutrons have opposite, but equal in magnitude, charges.

E) Neutrons and electrons are found in the nucleus of an atom.

18) Which of the following statements about isotopes is TRUE?

A) Isotopes of the same element differ only in the number of electrons they contain.

B) An isotope of an atom with a larger number of neutrons is larger than an isotope of the same atom

that contains fewer neutrons.

C) Isotopes of the same element have the same mass.

D) Isotopes of the same element don’t usually have the same properties.

E) Some elements have 3 or more naturally occurring isotopes.

19) Give the symbol for silver.

A) S

B) Si

C) Ar

D) Ag

E) Sl

20) Ions differ in the number of

A) electrons.

B) neutrons.

C) protons.

D) neutrons and protons.

E) electrons and protons.

21) What species is represented by the following information?

p+ = 12 n° = 14 e– = 10

A) Si4+

B) Mg

C) Ne

D) Si

E) Mg2+

22) What species is represented by the following information?

p+ = 47 n° = 62 e– = 46

A) Ag+

B) Nd

C) Pd

D) Ag

E) Pd+

23) What species is represented by the following information?

p+ = 17 n° = 18 e– = 18

A) Cl

B) Cl–

C) Ar

D) Ar+

E) Kr

24) Identify the largest atom or ion of carbon.

A) p+ = 6 n° = 6 e– = 6

B) p+ = 6 n° = 7 e– = 6

C) p+ = 6 n° = 6 e– = 7

D) p+ = 6 n° = 6 e– = 5

25) Predict the charge that an aluminum ion would have.

A) 5-

B) 1+

C) 1-

D) 2+

E) 3+

26) Predict the charge that a calcium ion would have.

A) 6-

B) 2-

C) 3+

D) 2+

E) 1+

27) Predict the charge that an ion formed from sulfur would have.

A) 1-

B) 6+

C) 3-

D) 4+

E) 2-

28) Predict the charge that an ion formed from sodium would have.

A) 1-

B) 6+

C) 3-

D) 1+

E) 2-

29) Which of the following elements is NOT a metal?

A) Ba

B) Mg

C) Xe

D) Pb

E) Ga

30) Which of the following elements is a lanthanide?

A) Ce

B) Na

C) U

D) Ar

E) Rg

31) Which of the following elements is a actinide?

A) Ce

B) Na

C) U

D) Ar

E) Rg

32) Which of the following statements is FALSE?

A) Halogens are very reactive elements.

B) The alkali metals are fairly unreactive.

C) Sulfur is a main group element.

D) Noble gases do not usually form ions.

E) Zn is a transition metal.

33) Which of the following does NOT describe a metal?

A) good conductor of heat

B) good conductor of electricity

C) tends to gain electrons

D) forms ionic compounds with nonmetals

E) found on the left side of the periodic table.

34) Which of the following does NOT describe a nonmetal?

A) tend to gain electrons

B) found in the upper right hand corner of the periodic table

C) poor conductor of electricity

D) nonmetals are generally unreactive

E) poor conductor of heat

35) Semiconductors are

A) metalloids.

B) noble gases.

C) nonmetals.

D) metals.

36) Which of the following statements is FALSE?

A) Anions are usually larger than their corresponding atom.

B) Metals tend to form cations.

C) Atoms are usually larger than their corresponding cation.

D) The halogens tend to form 1+ ions.

E) Nonmetals tend to gain electrons.

37) Identify the green-yellowish gas that is used as a disinfecting agent.

A) chlorine

B) bromine

C) iodine

D) fluorine

38) Identify the instrument that is used to determine the mass of a molecule.

A) mass spectrometer

B) nuclear magnetic resonance spectrometer

C) infrared spectrometer

D) gas chromatograph

E) ultraviolet spectrophotometer

39) The atomic mass for cadmium is

A) 48

B) 112.41

C) 40.08

D) 20

40) Calculate the atomic mass of silver if silver has 2 naturally occurring isotopes with the following

masses and natural abundances:

Ag-107 106.90509 amu 51.84%

Ag-109 108.90476 amu 48.46%

A) 107.90 amu

B) 108.00 amu

C) 107.79 amu

D) 108.32 amu

E) 108.19 amu

41) Calculate the atomic mass of gallium if gallium has 2 naturally occurring isotopes with the following

masses and natural abundances:

Ga-69 68.9256 amu 60.11%

Ga-71 70.9247 amu 39.89%

A) 69.72 amu

B) 69.93 amu

C) 70.00 amu

D) 69.80 amu

E) 70.68 amu

42) Silver has an atomic mass of 107.868 amu. The Ag-109 isotope (108.905 amu) is 48.16%. What is

the amu of the other isotope?

A) 106.905 amu

B) 106.908 amu

C) 106.903 amu

D) 106.911 amu

43) Gallium has an atomic mass of 69.723 amu. The Ga-69 (68.926 amu) is 60.11%. What is the amu

of the other isotope?

A) 70.924 amu

B) 70.928 amu

C) 70.932 amu

D) 70.920 amu

44) Calculate the atomic mass of element “X”, if it has 2 naturally occurring isotopes with the following

masses and natural abundances:

X-45 44.8776 amu 32.88%

X-47 46.9443 amu 67.12%

A) 46.26 amu

B) 45.91 amu

C) 46.34 amu

D) 46.84 amu

E) 44.99 amu

45) What mass (in mg) does 2.63 moles of nickel have?

A) 44.8 mg

B) 2.23 × 104 mg

C) 129 mg

D) 3.56 x 105 mg

E) 1.54 x 105 mg

46) How many moles of Kr are contained in 398 mg of Kr?

A) 4.75 × 10-3 moles Kr

B) 33.4 moles Kr

C) 2.11 × 10-4 moles Kr

D) 2.99 × 10-3 moles Kr

E) 1.19 × 10-4 moles Kr

47) How many moles of Cs are contained in 595 kg of Cs?

A) 2.23 × 102 moles Cs

B) 4.48 × 103 moles Cs

C) 7.91 × 104 moles Cs

D) 1.26 × 103 moles Cs

E) 5.39 × 102 moles Cs

48) How many iron atoms are contained in 354 g of iron?

A) 2.62 × 1025 Fe atoms

B) 2.13 × 1026 Fe atoms

C) 4.69 × 1024 Fe atoms

D) 3.82 × 1024 Fe atoms

E) 9.50 × 1022 Fe atoms

49) How many phosphorus atoms are contained in 158 kg of phosphorus?

A) 3.07 × 1027 phosphorus atoms

B) 2.95 × 1027 phosphorus atoms

C) 3.25 × 1028 phosphorus atoms

D) 1.18 × 1024 phosphorus atoms

E) 8.47 × 1024 phosphorus atoms

50) Calculate the mass (in kg) of 4.87 x 1025 atoms of Zn.

A) 5.29 kg

B) 1.89 kg

C) 8.09 kg

D) 1.24 kg

E) 1.09 kg

51) Calculate the mass (in ng) of 2.33 x 1020 atoms of oxygen.

A) 6.19 × 106 ng

B) 1.62 × 107 ng

C) 2.25 × 103 ng

D) 3.73 × 106 ng

E) 4.69 × 107 ng

52) How many xenon atoms are contained in 2.36 moles of xenon?

A) 3.92 × 1024 xenon atoms

B) 2.55 × 1023 xenon atoms

C) 1.42 × 1024 xenon atoms

D) 7.91 × 1025 xenon atoms

E) 1.87 × 1026 xenon atoms

53) How many argon atoms are contained in 7.66 x 105 mmol of argon?

A) 4.61 × 1026 Ar atoms

B) 1.84 × 1028 Ar atoms

C) 1.15 × 1028 Ar atoms

D) 7.86 × 1020 Ar atoms

E) 3.24 × 1026 Ar atoms

Algorithmic Questions

1) Identify the element that has an atomic number of 15.

A) sulfur

B) oxygen

C) phosphorus

D) silicon

2) Give the symbol for fluorine.

A) F

B) Fl

C) Fo

D) Fu

E) Fr

3) An atom of 131I contains ________ protons.

A) 53

B) 184

C) 78

D) 124

E) 131

4) An atom of 131Xe contains ________ electrons.

A) 131

B) 185

C) 77

D) 123

E) 54

5) The atomic number of an atom of 80Br is ________.

A) 115

B) 35

C) 45

D) 73

E) 80

6) How many electrons are in nickel?

A) 28

B) 30

C) 31

D) 30.7

E) 58.7

7) How many neutrons are in nickel?

A) 28

B) 30

C) 31

D) 30.7

E) 58.7

8) How many protons are in magnesium?

A) 12

B) 13

C) 14

D) 12.3

E) 24.3

9) An ion has 8 protons, 9 neutrons, and 10 electrons. The symbol for the ion is ________.

A) 17O2-

B) 17O2+

C) 19F+

D) 19F–

E) 17Ne2+

10) Isotopes differ in the number of ________.

A) beta particles

B) protons

C) electrons

D) neutrons

E) neutrons and protons