Which group on the periodic table contains elements that typically form ions with a 3− charge?

• A. Group 2 (Alkaline earth metals)
• B. Group 17 (Halogens)
• C. Group 15 (Nitrogen group)
• D. Group 16 (Oxygen group)

Answer: (C)

Verified step by step guidance

1. Identify the groups mentioned and their typical ionic charges: Group 2 elements usually form 2+ ions, Group 17 elements typically form 1- ions, Group 15 elements often form 3- ions, and Group 16 elements generally form 2- ions.
2. Recall that the charge on an ion is related to how many electrons an element gains or loses to achieve a full octet (8 electrons) in its valence shell.
3. For Group 15 elements, they have 5 valence electrons and tend to gain 3 electrons to complete their octet, resulting in a 3- charge.
4. Compare this with Group 17 elements (7 valence electrons, gain 1 electron for 1- charge) and Group 16 elements (6 valence electrons, gain 2 electrons for 2- charge).
5. Conclude that the group whose elements typically form ions with a 3- charge is Group 15, the Nitrogen group.