Which of the following represents the oxide ion?

• A. O
• B. O^2–
• C. O₂
• D. O^3–

Answer: (B)

Verified step by step guidance

1. Understand that an oxide ion is a negatively charged ion formed when oxygen gains electrons.
2. Recall that a neutral oxygen atom has 8 protons and typically 8 electrons. To form an oxide ion, oxygen gains additional electrons.
3. Recognize that gaining two electrons results in a charge of -2, as each electron carries a charge of -1.
4. Identify the chemical symbol for oxygen, which is 'O', and note that the oxide ion is represented as 'O' with a charge of -2.
5. Conclude that the correct representation of the oxide ion is 'O^2–', indicating the gain of two electrons and a resulting charge of -2.