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Chemical Bonding (Exercises)
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A. Matching: Match each term in Column B with the correct description in Column A.
Column A
Column B
1. A chemical formula that shows the arrangement of atoms in molecules
a. molecular compound
2. The weakest attractions that exist between molecules
b. van der Waals forces
3. A covalent bond in which one pair of electrons is shared between two
atoms
c. single covalent bond
4. A molecule in which one end is slightly negative and the other end is
slightly positive
d. polar molecule
e. structural formula
5. An electrically neutral group of atoms joined together by covalent bonds
f. coordinate covalent bond
6. Compound composed of cations and anions
g. halide ions
7. The forces of attraction that bind oppositely charged
ions together
h. alloy
8. Lowest whole-number ratio of ions in an ionic
compound
i. octet rule
9. A depiction of the valence electrons as dots around
the symbol for an element
j. formula unit
10. A mixture of two or more elements, at least one of
which is a metal
k. electron dot structure
11. The attraction of the free-floating valence electrons
for the positively charged metal ions
l. ionic compound
12. Ions of the halogen atoms
m. ionic bonds
13. The electron(s) in the highest occupied energy level
of an atom
n. chemical formula
14. Atoms in a compound tend to have the electron
configuration of a noble gas.
o. valence electrons
15. Shows the kinds and numbers of atoms in the
smallest representative unit of a substance
p. metallic bond
B. Multiple Choice: Choose the best answer and write its letter on the line.
1. All the elements in a particular group of the periodic table have the same number of
a. electrons.
c. valence electrons.
b. energy levels.
d. protons.
2. What is the number of valence electrons in an atom of Al?
a. 13
c. 10
b. 3
d. 8
3. Among the following, the element with six valence electrons is
a. C.
c. O.
b. Cs.
d. Ne.
4. The electron dot structure for Cl is
a.
b.
Cl
Cl
c.
Cl
d.
Cl
5. In general, metals react by:
a. losing valence electrons.
b. gaining valence electrons.
c. sharing valence electrons.
d. sometimes gaining and sometimes losing valence electrons.
6. An ion of K has the same electron configuration as
a. Na+.
b. Ca.
c. Ar.
d. Kr.
7. The outer energy level configuration for O2– is
a. 2s2.
b. 2s22p4.
c. 2s2 2p5.
d. 2s2 2p6.
8. The chemical properties of an element are largely determined by its
a. number of energy levels.
b. period number.
c. number of protons.
d. number of valence electrons.
9. Which of the following has a noble gas electron configuration?
a. Na
c. Al3+
+
b. Mg
d. Br
10. Atoms of Ca and S would be expected to react in a ratio of
a. 1:1.
c. 2:1.
b. 1:2.
d. 3:1.
11. The chemical formula for the ionic compound formed when elements of Ca and N react is
a. CaN.
c. Ca3N2.
b. Ca2N3.
d. Ca5N2.
12. In general, ionic compounds
a. are amorphous solids at room temperature.
b. conduct electricity when in the solid state.
c. conduct electricity when they are dissolved in water.
d. all of the above
13. Metals typically are
a. good conductors of electrical current.
b. malleable.
c. ductile.
d. all of the above
14. Which of the following is an anion?
a. O2–
b. Mg2+
c. Al3+
d. H
15. The nonmetals in Groups 5A, 6A, and 7A
a. lose electrons when they form ions.
b. form positively charged ions.
c. form ions with charges of 3–, 2–, and 1–, respectively.
d. form ions with a numerical charge equal to their group number.
16. Among the following, which atom is most likely to form an ion with a charge of 2+?
a. O
c. Al
b. Na
d. Ca
17. Which of the following exists as a diatomic molecule?
a. He
c. Cl
b. Ar
d. Na
18. The diatomic molecule among the following that contains a single covalent bond is
a. F2.
c. N2.
b. O2.
d. O2.
19. Atoms share electrons in order to acquire the electron configurations of
a. alkali metals.
c. halogens.
b. alkaline earth metals.
d. noble gases.
20. In Cl2, what is the total number of unshared pairs of electrons?
a. 1
c. 4
b. 2
d. 6
21. The diatomic molecule among the following that contains a triple covalent bond is
a. O2.
c. H2.
b. Cl2.
d. N2.
22. In the N2 molecule, what is the number of unshared pairs of electrons in each nitrogen atom?
a. 1
c. 3
b. 2
d. 4
23. The covalent molecule among the following is
a. NaCl.
c. CaO.
b. NH3.
d. KF.
24. How many single covalent bonds are there in a molecule of CH4?
a. 1
c. 3
b. 2
d. 4
25. How many double covalent bonds are there in a molecule of CO 2?
a. 1
c. 3
b. 2
d. 4
26. The molecule among the following that contains only one single covalent bond is
a. NH3.
c. HI.
b. N2.
d. H2O.
27. In forming the molecule HF, the F atom attains the electron configuration of
a. He.
c. Ar.
b. Ne.
d. Cl.
28. Which of the following contains a polar covalent bond?
a. O2
c. CaO
b. MgCl2
d. HF
29. What type of bond would be expected in a molecule of LiF?
a. ionic bond
c. nonpolar covalent bond
b. polar covalent bond
d. none of the above
30. Among the following molecules, the one containing the most polar bond is
a. HF.
c. HBr.
b. HCl.
d. H2O.
31. The polar molecule among the following is
a. CCl4.
c. H2O.
b. CO2.
d. N2.
32. The strongest intermolecular attractive forces from among those listed are
a. dispersion forces.
c. hydrogen bonds.
b. dipole interactions.
d. cannot be determined
33. The melting and boiling points of most molecular compounds are
a. lower than those of most ionic compounds.
b. about the same as those of most ionic compounds.
c. higher than those of most ionic compounds.
d. sometimes higher and sometimes lower than those of most ionic compounds.
34. Network solids
a. have low melting points.
c. are extremely hard.
b. have low boiling points.
d. are generally ductile.