Chapter 8 – Show all work or provide complete explanations.
1. (a) What is the octet rule? (b) How many electrons must a sulfur atom gain to
achieve octet?
2. What is the Lewis symbol for each of the following atoms or ions:
(a) Br; (b) Mg; (c) Ca2+; (d) F13. Using Lewis symbols, diagram the reaction that occurs between Mg and Cl.
4. Indicate whether each of the formulas is likely to represent a stable compound and
give an explanation for your answer: (a) Rb2O; (b) BaF; (c) Mg2O; (d) ScBr3;
(e) Na3N.
5. Write the electron configuration for each ion and state which possess a noble gas
configuration: (a) As3-; (b) Ag+; (c) Cs+; (d) Co2+; (e) Sc3+.
6. Does the lattice energy of an ionic solid increase or decrease as (a) the charges of
the ions increase; (b) as the sizes of the ions increase?
7. Explain the following trends in lattice energy: (a) MgOMgS; (b) LiFCsBr;
( c ) CaOKF.
8. (a) Why are monatomic anions larger than the corresponding neutral atoms?
(b) Why are monatomic cations smaller than their corresponding neutral atoms?
9. Select the ions or atoms from each of the following sets that are isoelectronic with
each other: (a) K+, Rb+, Ca2+; (b) Cu+, Ca2+, Sc3+; (c) S2-, Se2-, Ar; (d) Fe2+, Co3+,
10. Explain the following variations in atomic or ionic radii: (a) P3-S2-Cl1-; (b) Br1-
11. For each of the following sets of atoms and ions, arrange the members in order of
increasing size: (a) Se2-, Te2-, Se; (b) Co3+, Fe2+, Fe3+; (c) Ca, Ti4+, Sc3+, (d) Be2+,
Na+, Ne.
12. Using Lewis symbols and Lewis structures, diagram the formation of NF3 from N
and F atoms.
13. How does the number of shared electron pairs between atoms affect the distance
between the atoms?
14. (a) How does the electronegativity of the elements generally vary as you proceed
left to right in a row of the periodic table? (b) What is the general trend in electronegativity
as you proceed down a family of the periodic table? (c) How do the periodic trends in
electronegativity relate to those for ionization energy and electron affinity?
15. Using only the periodic table, select the most electronegative atom in each of the
Following sets: (a) Be, B, C, Si; (b) Cl, S, Br, Se; (c) Si, Ge, Al, Ga; (d) K, Ca, As, Se.
16. Arrange the bonds in each of the following sets in order of increasing polarity: (a)
N-F, N-Cl, N-Br; (b) H-F, O-F, B-F; (c) N-N, N-P, N-O.
17. Draw the Lewis structures for (a) PH3; (b) BrO31-; (c) CO; (d) HClO2; (e) SeCl2.
18. Write the Lewis structures for (a) BH41-; (b) H2O2; (c) HOCl; (d) C2H2; (e) ONCl.
19. Draw resonance structures for each of the following: (a) SO3; (b) C2O42-; (c) HNO3;
(d) ClO3.
20. Draw the resonance forms for the following: (a) NO21-; (b) CO32-; (c) SCN1-;
(d) HCO21-

Chapter 8 Homework