Chapter 2 - Atoms, Molecules, and Ions - Questions and Exercises - Exercises - Page 85: 2.58

(a) representative (b) transition metal (c) representative (d) transition metal

(a) Barium, or Ba, is a representative element because it is a main-group element, meaning it is in the "A" group elements. Barium is in group 2A of the periodic table. (b) Mo, or molybdenum, is a transition metal because it is in the middle section of the periodic table called the "B" section. Molybdenum is in group 6B of the periodic table. (c) F, or fluorine, is a representative element because it is a main-group element, meaning it is in the "A" group elements. Fluorine is in group 7A of the periodic table. (d) Hafnium, or Hf, is a transition metal because it is in the middle section of the periodic table called the "B" section. Hafnium is in group 4B of the periodic table.