1. © 2012 Pearson Education, Inc.
Molecular Geometry
© 2012 Pearson Education, Inc.

2. In the Lewis structure for sulfur, how many dots should be around the symbol “S”?
10.1 6 4 8 2 3
Answer: a

3. When electrons are completely transferred from one atom to another, the bond between the ions is called
10.2
polar covalent.
ionic.
polar ionic.
nonpolar covalent.
covalent.
Answer: b

4. Use Lewis theory to predict the chemical formula of the product formed by the reaction between aluminum and oxygen.
10.3
AlO
Al3O
Al3O2
Al2O3
Al3O3
Answer: d

5. How many valence electrons are there in one silicon atom?
10.5 3 6 14 4 8
Answer: d

6. How many electrons must a phosphorus atom gain in order to have a full valence shell?
10.6 2 3 1 5
Answer: b

7. How many electrons are there in the outer shell of an oxide ion?
10.7 8 2 4 6
Answer: a

8. How many bonding pairs of electrons are in one molecule of ammonia, NH3?
10.9 1 2 3 4
Answer: c

9. How many lone pairs of electrons are in one molecule of carbon tetrachloride?
10.10 4 6 8 12
Answer: e

10. Which of the following contains one or more double bonds?
10.11 F2 N2
CN– CO
SiO2
Answer: e

11. How many lone pairs are around the central atom in the ammonium ion?
10.13 1 4 12 16
Answer: c

12. What is the bond angle in a sulfur dioxide molecule?
10.14
180°
120°
90°
109.5°
104°
Answer: b

13. What is the electron geometry of boron trifluoride?
10.15
Linear
Trigonal planar
Tetrahedral
Trigonal pyramidal
Bent
Answer: b

14. What is the molecular geometry of NH2–?
10.16
Linear
Trigonal planar
Tetrahedral
Trigonal pyramidal
Bent
Answer: e

15. What is the electron geometry of a compound when the central atom is surrounded by 3 single bonds and 1 lone pair?
10.17
Linear
Trigonal planar
Tetrahedral
Trigonal pyramidal
Bent
Answer: c

16. Which of the following has a central atom that often does not obey the octet rule?
10.19
CH4
BF3
CCl4
NO3
NH4+
Answer: b

17. Which of the following contains a nonpolar, purely covalent bond?
10.20
NH3
CaCl2 I2
CO2 CO
Answer: c

18. Without using a table of electronegativity, arrange the following elements in order of increasing electronegativity: Cl, Te, Se, Sr, Ba
10.23
Cl, Te, Se, Sr, Ba
Cl, Te, Se, Ba, Sr
Ba, Sr, Te, Se, Cl
Sr, Ba, Te, Se, Cl
Ba, Sr, Se, Te, Cl
Answer: c

19. Which of the following has a bent molecular geometry?
10.27
HCN
CO2 HF
CH4
Two of the above
None of the above
Answer: f

20. Which of the following will exhibit trigonal pyramidal molecular geometry?
10.28
BH3
NO3–
NH3
CO32–
None of the above
Answer: c