## Chemistry: Principles and Practice (3rd Edition)

(a) ammonium bromide NH$_4$ stands for the polyatomic cation ammonium, and Br stands for the element bromine. To name the compound of these two elements, we take the exact name of the cation (ammonium), add the name of the anion (bromine), but change the ending of the anion to $-ide$. (b) barium chloride Looking at the periodic table, we can see that Ba stands for the element barium and Cl stands for the element chlorine. To name the compound of these two elements, we take the exact name of the cation (barium), add the name of the anion (chlorine), but change the ending of the anion to $-ide$. (c) potassium oxide Looking at the periodic table, we can see that K stands for the element potassium and O stands for oxygen. To name the compound of these two elements, we take the exact name of the cation (potassium) and add the name of the anion (oxygen), changing the ending to $-ide$. (d) strontium nitrate Looking at the periodic table, we can see that Sr stands for the element strontium. Referring back to Table 2.2 on page 65 of the book, we see that NO$_3$ stands for the polyatomic ion nitrate. To name the compound of these two elements, we take the exact name of the cation (strontium) and add the name of the anion (nitrate) as-is.