Which of the following best explains how two oxygen atoms bond together to form an O2 molecule?

• A. One oxygen atom donates electrons to the other, forming an ionic bond.
• B. They form a metallic bond by pooling their valence electrons.
• C. They share two pairs of electrons to form a double covalent bond.
• D. They share one pair of electrons to form a single covalent bond.

Answer: (C)

Verified step by step guidance

1. Step 1: Understand the types of chemical bonds. Ionic bonds form when one atom donates electrons to another, resulting in charged ions. Covalent bonds form when atoms share electrons. Metallic bonds involve a 'sea' of shared electrons among many atoms.
2. Step 2: Consider the nature of oxygen atoms. Oxygen is a nonmetal with six valence electrons and tends to achieve a full octet by sharing electrons rather than donating or pooling them like metals.
3. Step 3: Analyze the bonding in O2. Two oxygen atoms each need two more electrons to complete their octet, so they share two pairs of electrons between them.
4. Step 4: Recognize that sharing two pairs of electrons corresponds to a double covalent bond, which is stronger and shorter than a single covalent bond.
5. Step 5: Conclude that the best explanation is that two oxygen atoms share two pairs of electrons to form a double covalent bond, resulting in the O2 molecule.