Chapter 2 - Atoms, Molecules, and Ions - Exercises - Page 74: 2.7

Yellow box: 1+ (group 1A) Blue box: 2+ (group 2A) Black box: 3+ (a metal in Group 3A) Red box: 2- (a nonmetal in group 6A) Green box: 1- (a nonmetal in group 7A)

You can identify the charge by looking at the group number on the Periodic Table. A group 1A element has a +1 charge, 2A has 2+, 3A has 3+. Group 6A has 2-, and Group 7A has 1-.