What is the most common ionic charge of oxygen when it forms compounds?

• A. +1
• B. +2
• C. -1
• D. -2

Answer: (D)

Verified step by step guidance

1. Recall that oxygen is a nonmetal element in Group 16 of the periodic table, which means it typically gains electrons to achieve a full octet when forming compounds.
2. Understand that oxygen has 6 valence electrons and needs 2 more electrons to complete its octet, so it tends to gain 2 electrons when forming ions.
3. When oxygen gains 2 electrons, it forms an oxide ion with a charge of -2, represented as O^{2-}.
4. Recognize that the +1, +2, and -1 charges are not common for oxygen in typical ionic compounds because oxygen rarely loses electrons or gains only one electron.
5. Therefore, the most common ionic charge of oxygen in compounds is -2.