Answer
(a) lithium iodide
(b) magnesium nitride
(c) sodium phosphate
(d) barium perchlorate
Work Step by Step
(a) lithium iodide
Looking at the periodic table, we can see that Li stands for the element lithium and I stands for the element iodine. To name the compound of these two elements, we take the exact name of the cation (lithium), add the name of the anion (iodine), but change the ending of the anion to $-ide$.
(b) magnesium nitride
Looking at the periodic table, we can see that Mg stands for the element magnesium and N stands for the element nitrogen. To name the compound of these two elements, we take the exact name of the cation (magnesium), add the name of the anion (nitrogen), but change the ending of the anion to $-ide$.
(c) sodium phosphate
Looking at the periodic table, we can see that Na stands for the element sodium. Referring back to Table 2.2 on page 65 of the book, we see that PO$_4$ stands for the polyatomic ion phosphate. To name the compound of these two elements, we take the exact name of the cation (sodium) and add the name of the anion (phosphate) as-is.
(d) barium perchlorate
Looking at the periodic table, we can see that Ba stands for the element barium. Referring back to Table 2.2 on page 65 of the book, we see that ClO$_4$ stands for the polyatomic ion perchlorate. To name the compound of these two elements, we take the exact name of the cation (barium) and add the name of the anion (perchlorate) as-is.