Deck 2: Atoms, molecules, and Ions

Question 1

Rubidium has two naturally occurring isotopes.The average mass of Rb is 85.4678 amu.If 72.15% of Rb is found as Rb-85 (84.9117 amu),what is the mass of the other isotope?

A) 0.56 amu
B) 85.68 amu
C) 86.91 amu
D) 86.02 amu
E) 83.47 amu

Answer 1

86.91 amu

Question 2

What is the identity of ${ }_{25}^{55} \mathrm{X}$ ?

A) zinc
B) silver
C) iridium
D) cesium
E) manganese

Answer 2

manganese

Question 3

Two isotopes of chlorine are found in nature,Cl-35 and Cl-37.The average mass of chlorine is 35.45 amu.The more abundant isotope of Cl has

A) 17 protons,17 electrons,and 18 neutrons.
B) 17 protons,17 electrons,and 18.45 neutrons.
C) 17 protons,17 electrons,and 20 neutrons.
D) 18 protons,18 electrons,and 17 neutrons.
E) 19 protons,19 electrons,and 16 neutrons.

Answer 3

17 protons,17 electrons,and 18 neutrons.

Question 4

All atoms of the same element have the same number of ____.

A) neutrons
B) protons
C) protons and neutrons
D) electrons and neutrons
E) protons,neutrons,and electrons

Question 5

Which species has 63 neutrons?

A) ${ }_{43}^{112} \mathrm{Cd}$
B) ${ }_{49}^{112} \text { In }$
C) ${ }_{69}^{63} \mathrm{Cu}$
D) ${ }_{63}^{152} \mathrm{Eu}$
E) none of the above

Question 6

F-20,a radioactive isotope of fluorine,has

A) 9 protons,10 neutrons,and 1 electron.
B) 9 protons,10 neutrons,and 9 electrons.
C) 9 protons,11 neutrons,and 9 electrons.
D) 10 protons,9 neutrons,and 1 electron.
E) 10 protons,10 neutrons,and 10 electrons.

Question 7

Which two atoms below have the same number of neutrons?
${ }_{8}^{15} \mathrm{O}$ , ${ }_{8}^{16} \mathrm{O}$ , ${ }_{9}^{20} \mathrm{F}$ , ${ }_{20}^{20} \mathrm{Ne}$ , ${ }_{11}^{22} \mathrm{Na}$

A) ${ }_{8}^{15} \mathrm{O}$ and ${ }_{8}^{16} \mathrm{O}$
B) ${ }_{8}^{16} \mathrm{O}$ and ${ }_{11}^{22} \mathrm{Na}$
C) ${ }_{9}^{20} \mathrm{F}$ and ${ }_{20}^{20} \mathrm{Ne}$
D) ${ }_{9}^{20} \mathrm{F}$ and ${ }_{11}^{22} \mathrm{Na}$
E) ${ }_{20}^{20} \mathrm{Ne}$ and ${ }_{11}^{22} \mathrm{Na}$

Question 8

Which of the following atoms contains the fewest protons?

A) (²³²Th)
B) (²³¹Pa)
C) (²⁴⁵Pu)
D) (²³⁸U)
E) (²³²Pa)

Question 9

Silver has two stable isotopes with masses of 106.90509 amu and 108.9047 amu.The average molar mass of silver is 107.868 amu.What is the percent abundance of each isotope?

A) 50.0% Ag-107 and 50.0% Ag-109
B) 51.8% Ag-107 and 48.2% Ag-109
C) 55.4% Ag-107 and 44.6% Ag-109
D) 48.2% Ag-107 and 51.8% Ag-109
E) 44.6% Ag-107 and 55.4% Ag-109

Question 10

What is the mass number of an argon atom with 22 neutrons?

A) 2
B) 18
C) 22
D) 40
E) 39.95

Question 11

Which two of the ions below have the same number of electrons?
${ }_{53}^{127} \mathrm{I}^{-}$ , ${ }_{50}^{119} \mathrm{Sn}^{2+}$ , ${ }_{82}^{207} \mathrm{~Pb}^{2+}$ , ${ }_{82}^{207} \mathrm{~Pb}^{4+}$ , ${ }_{56}^{137} \mathrm{Ba}^{2+}$

A) ${ }_{53}^{127} \mathrm{I}^{-}$ and ${ }_{56}^{137} \mathrm{Ba}^{2+}$
B) ${ }_{53}^{127} \mathrm{I}^{-}$ and ${ }_{50}^{119} \mathrm{Sn}^{2+}$
C) ${ }_{82}^{207} \mathrm{~Pb}^{2+}$ and ${ }_{56}^{137} \mathrm{Ba}^{2+}$
D) ${ }_{50}^{119} \mathrm{Sn}^{2+}$ and ${ }_{56}^{137} \mathrm{Ba}^{2+}$
E) ${ }_{82}^{207} \mathrm{~Pb}^{2+}$ and ${ }_{82}^{207} \mathrm{~Pb}^{4+}$

Question 12

All of the following statements are true EXCEPT

A) all atoms of a given element have the same mass number.
B) for any neutral element,the number of electrons is equal to the number of protons.
C) the mass number is the sum of the number of protons and neutrons.
D) isotopes of atoms contain the same number of protons but a different number of neutrons.
E) the atomic number equals the number of protons in an atom.

Question 13

Gallium has an average atomic mass of 69.7 amu.In a typical sample,60.4% of Ga exists as Ga-69 (68.9257 amu).What is the identity and the atomic mass of the other isotope?

A) ${ }_{31}^{72} \mathrm{Ga}$ ;70.9 amu
B) ${ }_{31}^{70} \mathrm{Ga}$ ;70.9 amu
C) ${ }_{31}^{71} \mathrm{Ga}$ ;70.9 amu
D) ${ }_{31}^{71} \mathrm{Ga}$ ;71.9 amu
E) ${ }_{31}^{72} \mathrm{Ga}$ ;71.9 amu

Question 14

What is the symbol for an element which contains 57 neutrons and has a mass number of 101?

A) Er
B) Ru
C) Md
D) La
E) Os

Question 15

Two isotopes of a given element will have the same number of ____,but a different number of ____ in their nucleus.

A) protons,electrons
B) electrons,protons
C) protons,neutrons
D) neutrons,protons
E) electrons,neutrons

Question 16

The average molar mass of lithium is 6.941.A sample of lithium consists of two isotopes with masses of 6.01512 amu and 7.01600 amu.Determine the percent abundance of each isotope.

A) 7.49% Li-6 and 92.51% Li-7
B) 8.45% Li-6 and 91.55% Li-7
C) 12.49% Li-6 and 87.51% Li-7
D) 91.55% Li-6 and 8.45% Li-7
E) 92.51% Li-6 and 7.49% Li-7

Question 17

How many protons,neutrons,and electrons are in a silver atom with a mass number of 108?

A) 47 protons,47 neutrons,61 electrons
B) 47 protons,61 neutrons,47 electrons
C) 61 protons,47 neutrons,47 electrons
D) 47 protons,108 neutrons,47 electrons
E) 61 protons,108 neutrons,61 electrons

Question 18

Which of the following are a pair of isotopes?

A) ${ }_{18}^{40} \mathrm{Ar}$ and ${ }_{19}^{40} \mathrm{K}$
B) ${ }_{20}^{40} \mathrm{Ca}$ and ${ }_{19}^{40} \mathrm{K}$
C) ${ }_{18}^{40} \mathrm{Ar}$ and ${ }_{36}^{80} \mathrm{Kr}$
D) ${ }_{20}^{40} \mathrm{Ca}$ and ${ }_{19}^{39} \mathrm{~K}$
E) ${ }_{20}^{40} \mathrm{Ca}$ and ${ }_{20}^{42} \mathrm{Ca}$

Question 19

Rank the subatomic particles from least to greatest mass.

A) electrons = neutrons = protons
B) electrons = protons < neutrons
C) electrons < neutrons = protons
D) electrons < protons < neutrons
E) electrons < neutrons < protons

Question 20

What is the atomic symbol for an element with 39 protons and 50 neutrons?

A) ${ }_{81}^{89} \mathrm{Na}$
B) ${ }_{39}^{50} \mathrm{Y}$
C) ${ }_{39}^{89} \mathrm{Y}$
D) ${ }_{50}^{89} \mathrm{Sn}$
E) ${ }_{89}^{227} \mathrm{Ac}$

Question 21

Identify the ions and their charges in Na₂SO₄.

A) Na⁺,SO₄−
B) Na⁺,SO₄²⁻
C) Na⁺,SO⁴⁻
D) Na²⁺,SO⁴⁻
E) Na²⁺,SO₄²⁻

Question 22

How many elements are contained in period 2?

A) 3
B) 8
C) 10
D) 18
E) 32

Question 23

A strontium ion has ____ electrons.

A) 35
B) 36
C) 37
D) 38
E) 39

Question 24

Which two of the following elements are abundant in the Earth's crust,but missing from the human body: O,Al,Si,Fe,C,N?

A) O and Fe
B) Si and C
C) Al and Si
D) O and N
E) Fe and N

Question 25

The formula of ethanol,CH₃CH₂OH,is an example of a(n)

A) condensed formula.
B) empirical formula.
C) structural formula.
D) ionic compound formula.
E) molecular formula.

Question 26

What is the correct formula for an ionic compound that contains magnesium ions and phosphide ions?

A) MgP
B) MgP₂
C) Mg₃P₂
D) Mg₃(PO₄)₂
E) Mg₂P₃

Question 27

Which atom is most likely to form an ion with a +2 charge?

A) scandium
B) calcium
C) aluminum
D) oxygen
E) fluorine

Question 28

Which three elements are likely to have similar chemical and physical properties?

A) boron,silicon,and germanium
B) sodium,magnesium,and aluminum
C) sodium,potassium,and rubidium
D) oxygen,sulfur,and chlorine
E) carbon,nitrogen,and oxygen

Question 29

Which group of three elements contains a nonmetal,a metal,and a metalloid?

A) Li,Al,Si
B) Na,Hg,I
C) I,Hg,Si
D) K,O,Br
E) H,Al,N

Question 30

How many nonmetallic elements are there in group 13?

A) 0
B) 1
C) 2
D) 3
E) 4

Question 31

For a nonmetal in Group 16 of the periodic table,the most common monatomic ion will have a charge of ____.

A) -3
B) -2
C) -1
D) +1
E) +3

Question 32

Which group of three elements contains a transition metal,a halogen,and a noble gas?

A) S,I,Cu
B) Br,Kr,Ba
C) Ar,Hg,Rn
D) Ce,N,He
E) Cu,I,Xe

Question 33

Identify the ions and their charges in KH₂PO₄.

A) K⁺,H⁺,P³⁻,O²⁻
B) K⁺,H²⁺,P³⁻,O⁸⁻
C) K⁺,H₂²⁺,P−¹,O₄−²
D) K⁺,H₂PO₄−
E) K⁺,H²⁺,PO₄³⁻

Question 34

What is the mass (in grams)of a boron atom?

A) 10.8 g
B) 1.80 × 10^-23 g
C) 1.66 × 10^-24 g
D) 5.57 × 10²² g
E) 1.54 × 10^-25 g

Question 35

What element is in the fourth period in Group 3A?

A) Sb
B) Ga
C) In
D) Si
E) Tl

Question 36

What is the correct formula for an ionic compound that contains aluminum ions and chloride ions?

A) AlCl
B) AlCl₂
C) AlCl₃
D) Al₂Cl₃
E) Al₃Cl₂

Question 37

Group 1 elements are also known as

A) alkaline earth metals.
B) alkali metals.
C) chalcogens.
D) halogens.
E) noble gases.

Question 38

Which element is most likely to form an ion with a −2 charge?

A) K
B) Mg
C) P
D) Br
E) S

Question 39

Identify the halogen from period 4.

A) Br
B) I
C) Kr
D) Ar
E) K

Question 40

Of the naturally occurring elements in group 14,how many are nonmetals,metalloids,and metals?

A) 0 nonmetals,3 metalloids,and 2 metals
B) 1 nonmetal,2 metalloids,and 2 metals
C) 2 nonmetals,2 metalloids,and 1 metal
D) 2 nonmetals,1 metalloid,and 2 metals
E) 3 nonmetals,0 metalloids,and 2 metals

Question 41

What is the correct formula for sulfur dichloride?

A) SCl
B) SCl₂
C) S₂Cl
D) S₂Cl₂
E) S₄Cl₂

Question 42

What is the correct name for K₃PO₄?

A) tripotassium phosphate
B) potassium(I)monophosphorus tetraoxide
C) potassium(I)phosphate
D) potassium phosphate
E) potassium phosphide

Question 43

What is the formula for hypochlorous acid?

A) HCl
B) HClO
C) HClO₂
D) HClO₃
E) HClO₄

Question 44

What are the values for x and y,respectively,in Ca_xH_yPO₄?

A) 1 and 2
B) 2 and 1
C) 1 and 3
D) 2 and 2
E) 1 and 1

Question 45

Using the laws of constant composition and the conservation of mass,complete the molecular picture of hydrogen molecules (circles)reacting with chlorine molecules (squares)to give hydrogen chloride (HCl).

A)
B)
C)
D)
E) None of these are correct.

Question 46

What is the correct name for H₂SO₄(aq)?

A) sulfuric acid
B) sulfide acid
C) sulfurous acid
D) hydrogen sulfate acid
E) hydrogen sulfide acid

Question 47

What is the correct formula for potassium dichromate?

A) K₂Cr₂O₇
B) K₂(Cr₂O₇)₂
C) K₂CrO₄
D) K₂(CrO₄)₂
E) KCrO₄

Question 48

What is the correct name for PF₅?

A) phosphorus pentafluoride
B) phosphorus(V)fluorine
C) phosphorofluoride
D) pentafluorophosphorus
E) pentafluorophosphate

Question 49

What is the correct formula for iron(II)nitrate?

A) Fe₂(NO₃)₂
B) Fe₂NO₃
C) Fe(NO₃)₂
D) Fe₃N₂
E) FeNO₃

Question 50

What is the correct name for TiCl₄?

A) monotitanium tetrachloride
B) tetrachlorine titanate
C) titanium tetrachlorine
D) titanium(IV)tetrachloride
E) titanium(IV)chloride

Question 51

What is the correct name for CCl₄?

A) carbon chlorine
B) tetracarbon chloride
C) carbon tetrachloride
D) carbon(IV)chloride
E) tetrachlorocarbide

Question 52

Using the laws of constant composition and the conservation of mass,complete the molecular picture of hydrogen molecules (circles)reacting with oxygen molecules (squares)to give water.

A)
B)
C)
D)
E)

Question 53

What is the correct name for N₂O₃?

A) nitrogen oxide
B) nitrogen(II)oxide
C) nitrogen(III)oxide
D) trioxygen dinitride
E) dinitrogen trioxide

Question 54

What is the correct formula for barium perchlorate?

A) BaClO₄
B) BaClO₃
C) Ba(ClO₄)₂
D) Ba(ClO₃)₂
E) Ba(ClO₃)₃

Question 55

What is the correct name for MnS?

A) manganese sulfide
B) dimanganese sulfate
C) dimanganese sulfide
D) manganese(II)sulfate
E) manganese(II)sulfide

Question 56

Which of the following is a nonelectrolyte in water?

A) NaCl
B) SF₆
C) KNO₃
D) MgS
E) NH₄Cl

Question 57

Sodium sulfate has the chemical formula Na₂SO₄.Based on this information,the formula for chromium(III)sulfate is ____.

A) CrSO₄
B) Cr(SO₄)₃
C) Cr₂(SO₄)₃
D) Cr₂SO₄
E) Cr₃(SO₄)₂

Question 58

What is the correct name for Al₂O₃?

A) alum
B) aluminum trioxide
C) aluminum ozinide
D) aluminum oxide
E) dialuminum trioxide

Question 59

What is the correct formula for aluminum selenide?

A) AlSe
B) AlSe₂
C) Al₂Se
D) Al₂Se₃
E) Al₃Se₂