## Introductory Chemistry (5th Edition)

a. $^{16}_8O$ b. $^{19}_9F$ c. $^{23}_{11}Na$ d. $^{27}_{13}Al$
1. Calculate the mass number for each isotope: a. A = 8 + 8 = 16 b. A = 9 + 10 = 19 c. A = 11 + 12 = 23 d. A = 13 + 14 = 27 2. Write the isotopic symbol, using the mass number as a superscript, and the atomic number as a subscript. a. $^{16}_8O$ b. $^{19}_9F$ c. $^{23}_{11}Na$ d. $^{27}_{13}Al$ ** Consult Figure 4.9, page 102, to see the symbols and atomic numbers for each of these elements.