Chapter 2 - Atoms, Molecules, and Ions: Matter Starts Here - Problems - Page 70: 36

(a)

Option (b) is incorrect. Phosphorus (P) is in group 15 and normally forms a 3- ion. Option (c) is incorrect. Beryllium (Be) is in group 2 and normally forms a 2+ ion. Option (d) is incorrect. Aluminum (Al) can form 1+, 2+, and 3+ ions, but the most common one is the 3+ ion. Option (a) is correct. Sulfur (S) is in group 16 and normally forms a 2- ion.