compounds and molecules
Multiple Choice
Identify the choice that best completes the statement or answers the question.
____
1. Typically, atoms gain or lose electrons to achieve
a. an exchange of energy.
b. ionization.
c. a stable electron configuration.
d. vaporization.
____
2. The formation of an ionic bond involves the
a. transfer of electrons.
b. transfer of neutrons.
c. transfer of protons.
d. sharing of electrons.
____
3. Which statement best describes the properties of sodium chloride?
a. Sodium chloride is a malleable solid.
b. Solid sodium chloride is a good conductor of electric current.
c. Sodium chloride has a low melting point.
d. Liquid sodium chloride is a good conductor of electric current.
____
4. Which of the following is a typical property of an ionic compound?
a. low melting point
b. poor conductor of electric current when melted
c. tendency to shatter when struck
d. all of the above
____
5. Which of the following compounds does NOT contain molecules?
a. H2
c. CO2
b. NaCl
d. H2O
____
6. You see a structural formula in which the symbols for elements are connected by a long dash. You can
assume that the chemical bonds in the compound are
a. ionic.
c. metallic.
b. covalent.
d. unstable.
____
7. In a polar covalent bond,
a. electrons are shared equally between atoms.
b. a cation is bonded to an anion.
c. electrons are transferred between atoms.
d. electrons are not shared equally between atoms.
____
8. Water has a higher boiling point than expected because
a. there is so much water vapor in the atmosphere.
b. water molecules are not very massive.
c. hydrogen and oxygen form single covalent bonds.
d. of the strong attractions between polar water molecules.
____
9. Which phrase best describes a metallic bond?
a. a bond that is formed by a metal
b. the attraction between a metal anion and a shared pool of electrons
c. a bond that forms between a metal and a nonmetal
d. the attraction between a metal cation and a shared pool of electrons
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____ 10. Metallic bonding is similar to ionic bonding because
a. electrons are transferred between atoms.
b. electrons are shared between atoms.
c. the lattice that forms contains anions and cations.
d. there is an attraction between positively charged and negatively charged particles.
____ 11. What is the name given to the electrons in the highest occupied energy level of an atom?
a. orbital electrons
c. anions
b. valence electrons
d. cations
____ 12. Which of the following is true about an ionic compound?
a. It is a salt.
c. It is composed of anions and cations.
b. It is held together by ionic bonds.
d. all of the above
____ 13. Which of the following pairs of elements is most likely to form an ionic compound?
a. magnesium and fluorine
c. oxygen and chlorine
b. nitrogen and sulfur
d. sodium and aluminum
____ 14. Ionic compounds are normally in which physical state at room temperature?
a. Solid
c. gas
b. Liquid
d. plasma
____ 15. Which of the following is true about the melting temperature of potassium chloride?
a. The melting temperature is relatively high.
b. The melting temperature is variable and unpredictable.
c. The melting temperature is relatively low.
d. Potassium chloride does not melt.
____ 16. Under what conditions can potassium bromide conduct electricity?
a. only when melted
b. only when dissolved
c. only when it is in crystal form
d. only when melted or dissolved in water
____ 17. Which of the following is NOT a characteristic of most ionic compounds?
a. They are solids.
b. They have low melting points.
c. When melted, they conduct an electric current.
d. They are composed of metallic and nonmetallic elements.
____ 18. What is the basis of a metallic bond?
a. the attraction of metal ions to mobile electrons
b. the attraction between neutral metal atoms
c. the neutralization of protons by electrons
d. the attraction of oppositely charged ions
____ 19. An ionic bond is a bond between ____.
a. a cation and an anion
b. valence electrons and cations
c. the ions of two different metals
d. the ions of two different nonmetals
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____ 20. Why do atoms share electrons in covalent bonds?
a. to become ions and attract each other
b. to attain a noble-gas electron configuration
c. to become more polar
d. to increase their atomic numbers
____ 21. A bond formed between a silicon atom and an oxygen atom is likely to be ____.
a. ionic
c. polar covalent
b. coordinate covalent
d. nonpolar covalent
____ 22. Which of the following covalent bonds is the most polar?
a. H—F
c. H—H
b. H—C
d. H—N
____ 23. When an atom loses an electron, it becomes a
a. positive ion.
b. negative ion.
c. neutral ion.
d. neutral atom.
____ 24. An ionic bond is the attraction between
a. similarly charged ions.
b. oppositely charged ions.
c. neutral ions.
d. neutral atoms.
____ 25. 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
____ 26. 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.
____ 27. Which is a property shared by most molecular compounds?
a. high boiling point
b. high melting point
c. low melting point
d. nonpolar bonds
____ 28. 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.
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____ 29. A covalent bond in which electrons are shared unequally is
a. polar.
b. a double bond.
c. ionic.
d. polyatomic.
____ 30. 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
Completion
Complete each statement.
31. You are given the melting points of three unknown substances and are asked to predict which one is an
ionic compound. You would select the compound with the ____________________ melting point.
32. A polar covalent bond forms when ____________________ are not shared equally between atoms.
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compounds and molecules
Answer Section
MULTIPLE CHOICE
1. ANS:
2. ANS:
3. ANS:
4. ANS:
5. ANS:
6. ANS:
7. ANS:
8. ANS:
9. ANS:
10. ANS:
11. ANS:
12. ANS:
13. ANS:
14. ANS:
15. ANS:
16. ANS:
17. ANS:
18. ANS:
19. ANS:
20. ANS:
21. ANS:
22. ANS:
23. ANS:
24. ANS:
25. ANS:
26. ANS:
27. ANS:
28. ANS:
29. ANS:
30. ANS:
COMPLETION
C
A
D
C
B
B
D
D
D
D
B
D
A
A
A
D
B
A
A
B
C
A
A
B
B
B
C
B
A
C
.
.
31. ANS: highest
32. ANS: electrons
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