Chapter 2 - Atoms, Molecules, and Ions - Questions and Exercises - Exercises - Page 85: 2.54

(a) Lead (Pb) (b) Barium (Ba) (c) Lanthanum (La) (d) Bismuth (Bi)

(a) Elements in the same group are in the same column on the periodic table. The sixth period is the row that begins with cesium (Cs) and ends with radon (Rn). The element in this row that is in the same column as Ge (or germanium) is lead (Pb). (b) Elements in the same group are in the same column on the periodic table. The sixth period is the row that begins with cesium (Cs) and ends with radon (Rn). The element in this row that is in the same column as magnesium (or Mg) is barium (Ba). (c) Elements in the same group are in the same column on the periodic table. The sixth period is the row that begins with cesium (Cs) and ends with radon (Rn). The element in this row that is in the same column as Y (or yttrium) is lanthanum (La). (d) Elements in the same group are in the same column on the periodic table. The sixth period is the row that begins with cesium (Cs) and ends with radon (Rn). The element in this row that is in the same column as arsenic (or As) is bismuth (Bi).