## Chemistry: Molecular Approach (4th Edition)

a. $AgCl$ b. $Na_2S$ c. $Al_2S_3$ d. $KCl$
Use the table 3.2, and the figure 3.7 (Page 98), to see the charges of the ions: a. Silver has "+1" as its charge, and its symbol is "Ag", so its ion will be: $Ag^{+}$ (See figure 3.7) The chlorine ion is "$Cl^{-}$" (See table 3.2) Put these together, where the subscript number will be the charge of the other ion. $Ag_1Cl_1$: $AgCl$. b. Sodium has "+1" as its charge, and its symbol is "Na", so its ion will be: $Na^{+}$ (See figure 3.7) The sulfur ion is "$S^{2-}$" (See table 3.2) Put these together, where the subscript number will be the charge of the other ion. $Na$ will receive 2, and $S$ will receive 1. $Na_2S_1$: $Na_2S$. c. Aluminium has "+3" as its charge, and its symbol is "Al", so its ion will be: $Al^{3+}$ (See figure 3.7) The sulfur ion is "$S^{2-}$" (See table 3.2) Put these together, where the subscript number will be the charge of the other ion. $Al$ will receive 2, and $S$ will receive 3. $Al_2S_3$ d. Potassium has "+1" as its charge, and its symbol is "K", so its ion will be: $K^{+}$ (See figure 3.7) The chlorine ion is "$Cl^{-}$" (See table 3.2) Put these together, where the subscript number will be the charge of the other ion. $K$ will receive 1, and $Cl$ will receive 1. $K_1Cl_1 : KCl$