selenide -2 anion b. barium barium ion +2 cation phosphide ion -3 #1 Name the ions formed by these elements and classify them as anions or cations a. selenium selenide -2 anion b. barium barium ion +2 cation phosphide ion -3 anion c. phosphorus

#2How many electrons were lost or gained to form these ions? a. Fe3+ 3 lost 2 gained b. O2- 1 lost c. Cu+

Group A elements 1 8 2 3 4 5 6 7 The charge on the group A metals #3Key concept: Explain how the charges of Group A metal and nonmetal ions are related to their positions in the periodic table. Group A elements 1 8 2 3 4 5 6 7 The charge on the group A metals is just the group number. The charge on the non-metals is the group number minus 8

4 Key concept: How are the charges of some transition metal ions determined? By how many electrons they lose. This can sometimes be more than one number for a given transition metal.(example Cr2+ and Cr3+)

-ite or -ate examples: 5 Key concept: What are the usual endings for the names of polyatomic ions? -ite or -ate examples:

#6 What are the charges on ions of Group 1A, Group 3A(aluminum), and Group 5A?

anions have only one atom #7 How does a polyatomic anion differ from a monatomic anion? -1 -2 Chloride Cl-1 -2 polyatomic anions have more than one atom, monatomic anions have only one atom Oxide O-2 -1 Carbonate CO3-2 Nitrite NO2-1 -1 -1 -1 Hydroxide OH-1 Nitrate NO3-1 Hydrogen sulfate HSO4-1

#8 Write the symbol for the ion of each element. Classify the ion as an anion or a cation, and name the ion. a. potassium: K+ cation; potassium ion b. oxygen: O2- anion; oxide ion c. tin (2 electrons lost): Sn2+ cation; tin (II) d. bromine Br- anion bromide ion e. beryllium: Be2+ cation; beryllium ion f. cobalt (3 electrons lost): Co3+ cation; cobalt (III)

#9 Write the symbol or formula (including charges) for each of the following ions. a. ammonium ion NH41+ b. tin (II) ion Sn2+ c. chromate ion CrO42- d. nitrate ion NO31-