Chemistry Test.2

 

Multiple Choice

Identify the choice that best completes the statement or answers the question.

 

____       1.   Electrons involved in bonding between atoms are

a.

valence electrons.

b.

inside the nucleus.

c.

closest to the nucleus.

d.

positively charged.

 

 

____       2.   Each family in the periodic table has its own characteristic properties based on the number of

a.

neutrons.

b.

valence electrons.

c.

protons.

d.

ions.

 

 

____       3.   What is the greatest number of valence electrons an atom can have?

a.

2

b.

3

c.

8

d.

12

 

 

____       4.   If atoms of a halogen nonmetal (Group 17) gain one electron, the atoms then have

a.

no valence electrons.

b.

7 valence electrons.

c.

8 valence electrons.

d.

17 valence electrons.

 

 

____       5.   When an atom loses an electron, it becomes a

a.

positive ion.

b.

negative ion.

c.

neutral ion.

d.

neutral atom.

 

 

____       6.   An ionic bond is the attraction between

a.

similarly charged ions.

b.

oppositely charged ions.

c.

neutral ions.

d.

neutral atoms.

 

 

____       7.   Ions that are made of more than one atom are examples of

a.

polyatomic ions.

b.

negative ions.

c.

positive ions.

d.

neutral ions.

 

 

____       8.   Ionic compounds are electrically

a.

charged.

b.

positive.

c.

negative.

d.

neutral.

 

 

____       9.   Magnesium bromide is an ionic compound with the chemical formula MgBr2. What does the Ò2Ó tell you?

a.

Bromide has a 2 charge.

b.

There are two magnesium ions to every bromide ion.

c.

There are two bromide ions for every magnesium ion.

d.

Bromide has a 2+ charge.

 

 

____     10.   What is the chemical name for the compound with the formula Na2S?

a.

sodium fluoride

b.

magnesium sulfide

c.

lithium oxide

d.

sodium sulfide

 

 

____     11.   In the chemical formula for an ionic compound, which item is written first?

a.

positive ion

b.

negative ion

c.

subscript

d.

charge

 

 

____     12.   Which of the following is a characteristic property of ionic compounds?

a.

They have low melting points.

b.

They have low boiling points.

c.

They form hard, brittle crystals with characteristic shapes.

d.

They contain no charged particles.

 

 

____     13.   In what form can an ionic compound conduct electricity?

a.

as a solid

b.

when dissolved in water

c.

as a crystal

d.

when warmed slightly

 

 

____     14.   A chemical bond formed when two atoms share electrons is called a(n)

a.

ionic bond.

b.

covalent bond.

c.

polyatomic bond.

d.

crystal bond.

 

 

____     15.   What is a double bond?

a.

a bond between two atoms

b.

one pair of electrons shared between two atoms

c.

two pairs of electrons shared between two atoms

d.

two pairs of electrons shared between four atoms

 

 

____     16.   Which is a property shared by most molecular compounds?

a.

high boiling point

b.

high melting point

c.

low melting point

d.

nonpolar bonds

 

 

____     17.   Molecular compounds do not conduct electricity because they

a.

break up into ions.

b.

do not break up into ions.

c.

do not dissolve in water.

d.

have high melting points.

 

 

____     18.   A covalent bond in which electrons are shared unequally is

a.

polar.

b.

a double bond.

c.

ionic.

d.

polyatomic.

 

 

____     19.   Molecules that contain two polar bonds are

a.

ionic.

b.

always polar.

c.

always nonpolar.

d.

sometimes polar.

 

 

____     20.   Water is polar and oil is nonpolar. What happens when the two liquids are poured into the same container?

a.

Both liquids become nonpolar.

b.

A gas is produced.

c.

The liquids mix well.

d.

The liquids do not mix.

 

 

____     21.   A mixture that is made of two or more elements—one that is a metal—that has the properties of metal is a(n)

a.

polymer.

b.

monomer.

c.

alloy.

d.

ceramic.

 

 

____     22.   What is an advantage that alloys might have over many pure metals?

a.

Alloys occur naturally.

b.

Alloys resist rust.

c.

Alloys are weaker.

d.

Alloys can bend easily.

 

 

____     23.   Steel is an alloy of one or more elements combined with

a.

copper.

b.

gold.

c.

iron.

d.

lead.

 

 

____     24.   Which of the following properties is NOT characteristic of steel?

a.

does not readily react with water

b.

resistant to rust

c.

strength

d.

reacts readily with air

 

 

____     25.   Brass and steel are examples of

a.

alloys.

b.

elements.

c.

pure metals.

d.

valence electrons.

 

 

____     26.   What strong alloy, containing carbon, iron, and another metal like chromium or nickel, is used to make construction equipment, bicycle frames, and train rails?

a.

brass

b.

gold alloy

c.

silver

d.

steel

 

 

____     27.   Which of the following best describes a metal crystal?

a.

metal atoms held together by covalent bonds

b.

metal atoms held together by ionic bonds

c.

positive metal ions surrounded by freely moving valence electrons

d.

neutral metal atoms surrounded by freely moving valence electrons

 

 

____     28.   The attraction between a positive metal ion and the electrons surrounding it is a(n)

a.

chemical bond.

b.

covalent bond.

c.

ionic bond.

d.

metallic bond.

 

 

____     29.   Which of the following terms means that metals can be rolled into thin sheets, as in aluminum foil, or beaten into complex shapes?

a.

polar

b.

alloy

c.

ductile

d.

malleable

 

 

____     30.   Which of the following terms means that metals can be pulled into thin strands or wires?

a.

polar

b.

alloy

c.

ductile

d.

malleable

 

 

Modified True/False

Indicate whether the statement is true or false.  If false, change the identified word or phrase to make the statement true.

 

____     31.   The valence electrons are those electrons most tightly held by the atom. _________________________

 

____     32.   Each family in the periodic table has its own characteristic properties based upon its number of valence electrons. _________________________

 

____     33.   When an atom gains an electron it becomes a positive ion. _________________________

 

____     34.   The attraction between a positive ion and a negative ion results in a covalent bond. _________________________

 

____     35.   Orderly crystal shapes, high melting points, and electrical conductivity when dissolved in water are properties of ionic compounds. _________________________

 

____     36.   When electrons are transferred between two atoms, a covalent bond is formed. _________________________

 

____     37.   Low melting points and lack of electrical conductivity are properties of molecular compounds. _________________________

 

____     38.   A nonpolar bond is formed when two atoms share electrons unequally. _________________________

 

____     39.   In every alloy, at least one of the components is a(n) metal. _________________________

 

____     40.   Steel is an alloy of iron with carbon, nickel, and other elements. _________________________

 

Completion

Complete each statement.

 

             41.   Chemical bonds form when valence electrons are ____________________ between atoms.

 

             42.   A neutral atom never has more than ____________________ valence electrons.

 

             43.   In the periodic table, atoms are arranged from left to right and from top to bottom in order of increasing _________________________.

 

             44.   With the exception of helium, Group 18 elements usually have ______________ valence electrons, so they do not usually react with other elements.

 

             45.   Elements in Group 17 (the halogens) are the ____________________ reactive nonmetals.

 

             46.   Nitrate (NO3–), ammonium (NH4+), and carbonate (CO32–) are examples of ____________________ ions.

 

             47.   When ions having a positive charge form bonds with ions having a negative charge, the charge on the resulting compound is ____________________.

 

             48.   Elements in Group 1 lose one electron to form ions with a(n) ____________________ charge.

 

             49.   When an ionic compound forms, the total number of positive charges and the total number of negative charges must be ____________________.

 

             50.   Ionic compounds that dissolve in water conduct electricity because they break into ____________________ that move freely.

 

             51.   Ionic compounds have ____________ melting points because a lot of energy is needed to break the bonds between the ions.

 

             52.   Bonds that form between two nonmetal atoms usually are ____________________ bonds.

 

             53.   In a double covalent bond, ____________________ electrons are shared between two atoms.

 

             54.   Molecular compounds that dissolve in water do not conduct electricity because no _________________________ are present.

 

             55.   A(n) ____________________ compound is a compound that consists of molecules made of atoms that are covalently bonded.

 

             56.   Fluorine (F2) is a(n) ____________________ molecule because the valence electrons are shared equally between the two fluorine atoms.

 

             57.   Because the electrons in a molecule of hydrogen fluoride (HF) are more strongly pulled toward the fluorine atom, the molecule is ____________________.

 

             58.   Many ____________________ are made by melting metals and mixing them together in carefully measured amounts.

 

             59.   A metal crystal consists of positively charged metal ions embedded in a ÒseaÓ of freely moving _________________________ electrons.

 

             60.   Solid metals are good conductors of heat and ____________________.

 

Short Answer

 

Use the diagram to answer each question.

 

 

             61.   List three elements from the group containing the most reactive nonmetals.

 

             62.   In each period, how does the number of electrons in each kind of atom change from left to right between Groups 1 and 2? Explain how you know.

 

             63.   In an electron dot diagram of aluminum (Al), how many dots should be drawn around the elementÕs symbol? Why?

 

             64.   Which group of elements loses electrons most easily?

 

             65.   Which group contains elements with two valence electrons?

 

             66.   How many atoms of a Group 17 element would be needed to react with one atom of a Group 2 element? Explain.

 

Use the table below to answer the following questions.

 

Ions and Their Charges

Name

Charge

Symbol or Formula

Lithium

_?_

Li+

____?___

1+

Na+

Calcium

2+

___?__

Chloride

1–

___?__

___?____

1–

NO3

Carbonate

2–

___?___

 

 

             67.   What is the charge for a lithium ion?  

 

             68.   What is the symbol for a calcium ion?

 

             69.   What is the name of the ion with the chemical formula NO3–?

 

             70.   Which of these ions are polyatomic? Explain.

 

             71.   What is the chemical formula of the compound that forms when sodium and chloride combine?

 

             72.   What is the chemical name for CaCO3?

 

Essay

 

             73.   How do valence electrons relate to the chemical reactions of an element?

 

             74.   Explain what makes the Group 1 elements the most reactive metals.

 

             75.   Compare a covalent bond and an ionic bond.

 

             76.   Describe properties that would help you to distinguish an ionic compound from a molecular compound.

 

             77.   Explain what is meant by the term Òpolar bond.Ó

 

             78.   Why are alloys often more useful than pure metals?

 

             79.   Explain why metals are such good conductors of heat and electricity.

Chemistry Test.2

Answer Section

 

MULTIPLE CHOICE

 

               1.   ANS:   A                     PTS:    1                      DIF:    L2                  

OBJ:    CaPS.5.1.1 Explain how the reactivity of elements is related to valence electrons in atoms.

STA:   S 8.3.a             BLM:  comprehension           

 

               2.   ANS:   B                     PTS:    1                      DIF:    L2                  

OBJ:    CaPS.5.1.2 State what the periodic table tells you about atoms and the properties of elements.

STA:   S 8.3.a             BLM:  comprehension           

 

               3.   ANS:   C                     PTS:    1                      DIF:    L1                  

OBJ:    CaPS.5.1.2 State what the periodic table tells you about atoms and the properties of elements.

STA:   S 8.3.a             BLM:  knowledge

 

               4.   ANS:   C                     PTS:    1                      DIF:    L2                  

OBJ:    CaPS.5.1.2 State what the periodic table tells you about atoms and the properties of elements.

STA:   S 8.7.a             BLM:  application

 

               5.   ANS:   A                     PTS:    1                      DIF:    L1                  

OBJ:    CaPS.5.2.1 Explain how ions form bonds.                            STA:   S 8.3.a

BLM:  knowledge

 

               6.   ANS:   B                     PTS:    1                      DIF:    L1                  

OBJ:    CaPS.5.2.1 Explain how ions form bonds.                            STA:   S 8.3.c

BLM:  knowledge

 

               7.   ANS:   A                     PTS:    1                      DIF:    L1                  

OBJ:    CaPS.5.2.1 Explain how ions form bonds.                            STA:   S 8.3.b

BLM:  knowledge

 

               8.   ANS:   D                     PTS:    1                      DIF:    L2                  

OBJ:    CaPS.5.2.1 Explain how ions form bonds.                            STA:   S 8.3.b

BLM:  comprehension           

 

               9.   ANS:   C                     PTS:    1                      DIF:    L2                  

OBJ:    CaPS.5.2.2 Explain how the formulas and names of ionic compounds are written.

STA:   S 8.3.b            BLM:  application

 

             10.   ANS:   D                     PTS:    1                      DIF:    L2                  

OBJ:    CaPS.5.2.2 Explain how the formulas and names of ionic compounds are written.

STA:   S 8.3.b            BLM:  application

 

             11.   ANS:   A                     PTS:    1                      DIF:    L1                  

OBJ:    CaPS.5.2.2 Explain how the formulas and names of ionic compounds are written.

STA:   S 8.3.b            BLM:  knowledge

 

             12.   ANS:   C                     PTS:    1                      DIF:    L2                  

OBJ:    CaPS.5.2.3 Identify the properties of ionic compounds.        STA:   S 8.7.c

BLM:  comprehension           

 

             13.   ANS:   B                     PTS:    1                      DIF:    L1                  

OBJ:    CaPS.5.2.3 Identify the properties of ionic compounds.        STA:   S 8.3.b

BLM:  knowledge

 

             14.   ANS:   B                     PTS:    1                      DIF:    L1                  

OBJ:    CaPS.5.3.1 State what holds covalently bonded atoms together.      

STA:   S 8.3.b            BLM:  knowledge

 

             15.   ANS:   C                     PTS:    1                      DIF:    L2                  

OBJ:    CaPS.5.3.1 State what holds covalently bonded atoms together.      

STA:   S 8.3.b            BLM:  comprehension           

 

             16.   ANS:   C                     PTS:    1                      DIF:    L2                  

OBJ:    CaPS.5.3.2 Identify the properties of molecular compounds.            

STA:   S 8.3.b | S 8.7.c                                  BLM:  comprehension           

 

             17.   ANS:   B                     PTS:    1                      DIF:    L2                  

OBJ:    CaPS.5.3.2 Identify the properties of molecular compounds.            

STA:   S 8.3.b | S 8.7.c                                  BLM:  application

 

             18.   ANS:   A                     PTS:    1                      DIF:    L1                  

OBJ:    CaPS.5.3.3 Explain how unequal sharing of electrons occurs and how it affects molecules.

STA:   S 8.3.b            BLM:  knowledge

 

             19.   ANS:   D                     PTS:    1                      DIF:    L2                  

OBJ:    CaPS.5.3.3 Explain how unequal sharing of electrons occurs and how it affects molecules.

STA:   S 8.3               BLM:  comprehension           

 

             20.   ANS:   D                     PTS:    1                      DIF:    L2                  

OBJ:    CaPS.5.3.3 Explain how unequal sharing of electrons occurs and how it affects molecules.

STA:   S 8.3.b | S 8.7.c                                  BLM:  application

 

             21.   ANS:   C                     PTS:    1                      DIF:    L1                  

OBJ:    CaPS.5.4.1 Explain how the properties of metals and alloys compare.

STA:   S 8.7.c             BLM:  knowledge

 

             22.   ANS:   B                     PTS:    1                      DIF:    L2                  

OBJ:    CaPS.5.4.1 Explain how the properties of metals and alloys compare.

STA:   S 8.7.c             BLM:  application

 

             23.   ANS:   C                     PTS:    1                      DIF:    L2                  

OBJ:    CaPS.5.4.1 Explain how the properties of metals and alloys compare.

STA:   S 8.7.c             BLM:  comprehension           

 

             24.   ANS:   D                     PTS:    1                      DIF:    L2                  

OBJ:    CaPS.5.4.1 Explain how the properties of metals and alloys compare.

STA:   S 8.7.c             BLM:  application

 

             25.   ANS:   A                     PTS:    1                      DIF:    L2                  

OBJ:    CaPS.5.4.1 Explain how the properties of metals and alloys compare.

STA:   S 8.7.c             BLM:  application

 

             26.   ANS:   D                     PTS:    1                      DIF:    L2                  

OBJ:    CaPS.5.4.1 Explain how the properties of metals and alloys compare.

STA:   S 8.7.c             BLM:  application

 

             27.   ANS:   C                     PTS:    1                      DIF:    L2                  

OBJ:    CaPS.5.4.2 Describe how metal atoms are bonded in solid metal.    

STA:   S 8.3.c             BLM:  comprehension           

 

             28.   ANS:   D                     PTS:    1                      DIF:    L1                  

OBJ:    CaPS.5.4.2 Describe how metal atoms are bonded in solid metal.    

STA:   S 8.3.a | S 8.3.b                                  BLM:  knowledge

 

             29.   ANS:   D                     PTS:    1                      DIF:    L1                  

OBJ:    CaPS.5.4.3 Explain how metallic bonding results in useful properties of metals.

STA:   S 8.7.c             BLM:  knowledge

 

             30.   ANS:   C                     PTS:    1                      DIF:    L1                  

OBJ:    CaPS.5.4.3 Explain how metallic bonding results in useful properties of metals.

STA:   S 8.7.c             BLM:  knowledge

 

MODIFIED TRUE/FALSE

 

             31.   ANS:   F, loosely

 

PTS:    1                      DIF:    L1                  

OBJ:    CaPS.5.1.1 Explain how the reactivity of elements is related to valence electrons in atoms.

STA:   S 8.3.a             BLM:  knowledge

 

             32.   ANS:   T                                                         PTS:    1                      DIF:    L2

OBJ:    CaPS.5.1.1 Explain how the reactivity of elements is related to valence electrons in atoms.

STA:   S 8.7.a             BLM:  comprehension           

 

             33.   ANS:   F

 

negative

 

PTS:    1                      DIF:    L2                   OBJ:    CaPS.5.2.1 Explain how ions form bonds.

STA:   S 8.3.b            BLM:  comprehension           

 

             34.   ANS:   F, an ionic

 

PTS:    1                      DIF:    L1                   OBJ:    CaPS.5.2.1 Explain how ions form bonds.

STA:   S 8.3.b            BLM:  knowledge

 

             35.   ANS:   T                                                         PTS:    1                      DIF:    L2

OBJ:    CaPS.5.2.3 Identify the properties of ionic compounds.        STA:   S 8.3.c | S 8.7.c

BLM:  comprehension           

 

             36.   ANS:   F, shared

 

PTS:    1                      DIF:    L2                  

OBJ:    CaPS.5.3.1 State what holds covalently bonded atoms together.      

STA:   S 8.3.b            BLM:  comprehension           

 

             37.   ANS:   T                                                         PTS:    1                      DIF:    L2

OBJ:    CaPS.5.3.2 Identify the properties of molecular compounds.            

STA:   S 8.7.c             BLM:  comprehension           

 

             38.   ANS:   F, polar

 

PTS:    1                      DIF:    L1                  

OBJ:    CaPS.5.3.3 Explain how unequal sharing of electrons occurs and how it affects molecules.

STA:   S 8.3.b            BLM:  knowledge

 

             39.   ANS:   T                                                         PTS:    1                      DIF:    L1

OBJ:    CaPS.5.4.1 Explain how the properties of metals and alloys compare.

STA:   S 8.7.a             BLM:  knowledge

 

             40.   ANS:   T                                                         PTS:    1                      DIF:    L2

OBJ:    CaPS.5.4.1 Explain how the properties of metals and alloys compare.

STA:   S 8.7.c             BLM:  application

 

COMPLETION

 

             41.   ANS:  

transferred

shared

 

PTS:    1                      DIF:    L2                  

OBJ:    CaPS.5.1.1 Explain how the reactivity of elements is related to valence electrons in atoms.

STA:   S 8.3.b            BLM:  comprehension           

 

             42.   ANS:   eight

 

PTS:    1                      DIF:    L2                  

OBJ:    CaPS.5.1.1 Explain how the reactivity of elements is related to valence electrons in atoms.

STA:   S 8.3.a             BLM:  comprehension           

 

             43.   ANS:   atomic number

 

PTS:    1                      DIF:    L1                  

OBJ:    CaPS.5.1.2 State what the periodic table tells you about atoms and the properties of elements.

STA:   S 8.7.b            BLM:  knowledge

 

             44.   ANS:   eight

 

PTS:    1                      DIF:    L2                  

OBJ:    CaPS.5.1.2 State what the periodic table tells you about atoms and the properties of elements.

STA:   S 8.7.a             BLM:  comprehension           

 

             45.   ANS:   most

 

PTS:    1                      DIF:    L2                  

OBJ:    CaPS.5.1.2 State what the periodic table tells you about atoms and the properties of elements.

STA:   S 8.7.a             BLM:  comprehension           

 

             46.   ANS:   polyatomic

 

PTS:    1                      DIF:    L2                   OBJ:    CaPS.5.2.1 Explain how ions form bonds.

STA:   S 8.3.c | S 8.3.f                                   BLM:  application

 

             47.   ANS:   zero

 

PTS:    1                      DIF:    L2                   OBJ:    CaPS.5.2.1 Explain how ions form bonds.

STA:   S 8.3.b            BLM:  application

 

             48.   ANS:  

1+

1 positive

 

PTS:    1                      DIF:    L2                   OBJ:    CaPS.5.2.1 Explain how ions form bonds.

STA:   S 8.3.b | S 8.7.a                                  BLM:  application

 

             49.   ANS:   equal

 

PTS:    1                      DIF:    L2                   OBJ:    CaPS.5.2.1 Explain how ions form bonds.

STA:   S 8.3.b            BLM:  comprehension           

 

             50.   ANS:   ions

 

PTS:    1                      DIF:    L2                  

OBJ:    CaPS.5.2.3 Identify the properties of ionic compounds.        STA:   S 8.3.b

BLM:  comprehension           

 

             51.   ANS:   high

 

PTS:    1                      DIF:    L2                  

OBJ:    CaPS.5.2.3 Identify the properties of ionic compounds.        STA:   S 8.3.b

BLM:  comprehension           

 

             52.   ANS:   covalent

 

PTS:    1                      DIF:    L2                  

OBJ:    CaPS.5.3.1 State what holds covalently bonded atoms together.      

STA:   S 8.3.b            BLM:  comprehension           

 

             53.   ANS:  

four

two pairs of

 

PTS:    1                      DIF:    L2                  

OBJ:    CaPS.5.3.1 State what holds covalently bonded atoms together.      

STA:   S 8.3.b            BLM:  application

 

             54.   ANS:  

charged particles

charged ions

 

PTS:    1                      DIF:    L2                  

OBJ:    CaPS.5.3.2 Identify the properties of molecular compounds.            

STA:   S 8.3.b            BLM:  comprehension           

 

             55.   ANS:   molecular

 

PTS:    1                      DIF:    L2                  

OBJ:    CaPS.5.3.2 Identify the properties of molecular compounds.            

STA:   S 8.3.b            BLM:  comprehension           

 

             56.   ANS:   nonpolar

 

PTS:    1                      DIF:    L2                  

OBJ:    CaPS.5.3.3 Explain how unequal sharing of electrons occurs and how it affects molecules.

STA:   S 8.7.c             BLM:  application

 

             57.   ANS:   polar

 

PTS:    1                      DIF:    L3                  

OBJ:    CaPS.5.3.3 Explain how unequal sharing of electrons occurs and how it affects molecules.

STA:   S 8.7.c             BLM:  application

 

             58.   ANS:   alloys

 

PTS:    1                      DIF:    L1                  

OBJ:    CaPS.5.4.1 Explain how the properties of metals and alloys compare.

STA:   S 8.7.c             BLM:  knowledge

 

             59.   ANS:   valence

 

PTS:    1                      DIF:    L1                  

OBJ:    CaPS.5.4.2 Describe how metal atoms are bonded in solid metal.    

STA:   S 8.3.b            BLM:  knowledge

 

             60.   ANS:   electricity

 

PTS:    1                      DIF:    L2                  

OBJ:    CaPS.5.4.3 Explain how metallic bonding results in useful properties of metals.

STA:   S 8.7.c             BLM:  comprehension           

 

SHORT ANSWER

 

             61.   ANS:  

Accept any three elements from Group 17: fluorine (F), chlorine (Cl), bromine (Br), iodine (I), astatine (At).

 

PTS:    1                      DIF:    L2                  

OBJ:    CaPS.5.1.2 State what the periodic table tells you about atoms and the properties of elements.

STA:   S 8.7.a             BLM:  analysis

 

             62.   ANS:  

From Group 1 to Group 2, the number of electrons in each kind of atom increases by one in each period. This is the case because the number of protons (atomic number) increases by one from Group 1 to Group 2, and atoms have equal numbers of electrons and protons.

 

PTS:    1                      DIF:    L3                  

OBJ:    CaPS.5.1.2 State what the periodic table tells you about atoms and the properties of elements.

STA:   S 8.7.a             BLM:  analysis

 

             63.   ANS:  

Three. Elements in Group 13 have 3 valence electrons.

 

PTS:    1                      DIF:    L2                  

OBJ:    CaPS.5.1.2 State what the periodic table tells you about atoms and the properties of elements.

STA:   S 8.3.a             BLM:  application

 

             64.   ANS:  

Group 1

 

PTS:    1                      DIF:    L2                  

OBJ:    CaPS.5.1.2 State what the periodic table tells you about atoms and the properties of elements.

STA:   S 8.7.a             BLM:  analysis

 

             65.   ANS:  

Group 2

 

PTS:    1                      DIF:    L2                  

OBJ:    CaPS.5.1.2 State what the periodic table tells you about atoms and the properties of elements.

STA:   S 8.7.a             BLM:  analysis

 

             66.   ANS:  

Two. Atoms of elements in Group 17 form ions with a charge of 1–, and atoms of elements in Group 2 form ions with a charge of 2+. It would take two ions of a Group 17 element to balance the charge of one ion of a Group 2 element.

 

PTS:    1                      DIF:    L3                   OBJ:    CaPS.5.2.1 Explain how ions form bonds.

STA:   S 8.7.a             BLM:  synthesis

 

             67.   ANS:  

1+

 

PTS:    1                      DIF:    L2                   OBJ:    CaPS.5.2.1 Explain how ions form bonds.

STA:   S 8.3.a             BLM:  analysis

 

             68.   ANS:  

Ca2+

 

PTS:    1                      DIF:    L2                   OBJ:    CaPS.5.2.1 Explain how ions form bonds.

STA:   S 8.3.a             BLM:  analysis

 

             69.   ANS:  

Nitrate

 

PTS:    1                      DIF:    L3                   OBJ:    CaPS.5.2.1 Explain how ions form bonds.

STA:   S 8.3.f             BLM:  analysis

 

             70.   ANS:  

Nitrate (NO3–) and carbonate (CO32–)  are polyatomic ions, because they are made of more than one atom.

 

PTS:    1                      DIF:    L3                   OBJ:    CaPS.5.2.1 Explain how ions form bonds.

STA:   S 8.3.f             BLM:  analysis

 

             71.   ANS:  

NaCl

 

PTS:    1                      DIF:    L2                  

OBJ:    CaPS.5.2.2 Explain how the formulas and names of ionic compounds are written.

STA:   S 8.3.f             BLM:  analysis

 

             72.   ANS:  

calcium carbonate

 

PTS:    1                      DIF:    L3                  

OBJ:    CaPS.5.2.2 Explain how the formulas and names of ionic compounds are written.

STA:   S 8.3.f             BLM:  analysis

 

ESSAY

 

             73.   ANS:  

Valence electrons are the electrons that are most loosely held by the atom and the ones that are involved in chemical reactions. Chemical reactions occur whenever valence electrons are shared or transferred between atoms. The number of valence electrons determines how these reactions take place and what kind of bonds atoms can form.

 

PTS:    1                      DIF:    L3                  

OBJ:    CaPS.5.1.1 Explain how the reactivity of elements is related to valence electrons in atoms.

STA:   S 8.3.a             BLM:  synthesis

 

             74.   ANS:  

Atoms of Group 1 elements each have a single valence electron. These atoms easily lose their valence electron, reacting with other elements that can gain electrons, and therefore becoming more chemically stable. The easy loss of the one valence electron makes the Group 1 elements more reactive than metals that must lose two or three electrons in reactions.

 

PTS:    1                      DIF:    L3                  

OBJ:    CaPS.5.1.2 State what the periodic table tells you about atoms and the properties of elements.

STA:   S 8.7.a             BLM:  synthesis

 

             75.   ANS:  

A covalent bond is formed when two atoms share valence electrons. Neither atom loses electrons or takes electrons from the other. No charged particles form. In an ionic bond, one or more electrons are transferred from one atom to another. Atoms that lose electrons become positively charged ions, and atoms that gain electrons become negatively charged ions. These oppositely charged particles then attract each other.

 

PTS:    1                      DIF:    L2                  

OBJ:    CaPS.5.2.1 Explain how ions form bonds. | CaPS.5.3.1 State what holds covalently bonded atoms together.           STA:   S 8.3.b BLM:  analysis

 

             76.   ANS:  

Ionic compounds have high melting points and high boiling points compared to molecular compounds. Ionic compounds that are dissolved in water or melted will conduct electricity. Molecular compounds do not conduct electricity in either case.

 

PTS:    1                      DIF:    L2                  

OBJ:    CaPS.5.2.3 Identify the properties of ionic compounds. |  CaPS.5.3.2 Identify the properties of molecular compounds.                   STA:   S 8.3.b | S 8.7.c   

BLM:  analysis

 

             77.   ANS:  

When two atoms form a covalent bond, electrons are shared between them. If the atoms are different, one atom may pull more strongly on the shared electrons so that the electrons are shared unequally. This difference results in a bond that is slightly negative at one end and slightly positive at the other end. This unequal sharing of electrons is known as a polar bond.

 

PTS:    1                      DIF:    L2                  

OBJ:    CaPS.5.3.3 Explain how unequal sharing of electrons occurs and how it affects molecules.

STA:   S 8.3.b            BLM:  comprehension           

 

             78.   ANS:  

Alloys are usually stronger, harder, and more resistant to chemical reactions than pure metals. However, alloys still have metallic properties, such as the ability to conduct heat and electricity. The properties of alloys often make them more useful than pure metals in tools, machines, and other items.

 

PTS:    1                      DIF:    L2                  

OBJ:    CaPS.5.4.1 Explain how the properties of metals and alloys compare.

STA:   S 8.7.c             BLM:  comprehension           

 

             79.   ANS:  

A metal crystal consists of positively charged metal ions embedded in a ÒseaÓ of loosely held valence electrons that can move around easily. Heat travels through materials as the increased motion of the particles in the hotter parts of the material is passed along to the particles in the cooler parts. In a metal, since particles are easily set into motion, heat is easily transferred, or conducted. The same is true for the conduction of electricity. Electricity can flow when charged particles, like electrons, are free to move. Since the electrons in a metal crystal can move freely among the atoms, electricity is easily conducted.

 

PTS:    1                      DIF:    L3                  

OBJ:    CaPS.5.4.3 Explain how metallic bonding results in useful properties of metals.

STA:   S 8.7.c             BLM:  synthesis