Composition of a diatomic oxygen molecule A single molecule of elemental oxygen (written as O2) consists of how many oxygen atoms?

Introduction / Context:
Molecular formulas indicate the number and type of atoms in a molecule. Diatomic elements, such as oxygen and nitrogen, naturally occur as two-atom molecules under standard conditions, which affects molar mass, gas behavior, and reaction stoichiometry.

Given Data / Assumptions:

• Chemical symbol O2 denotes molecular oxygen.
• Standard ambient conditions for elemental form.
• Stoichiometry based on subscripts in molecular formulas.

Concept / Approach:

The subscript “2” in O2 specifies two oxygen atoms bound together. This diatomic nature explains the molar mass of oxygen gas (≈ 32 g/mol) and influences kinetic-theory properties (e.g., rotational modes) in thermodynamics.

Step-by-Step Solution:

Verification / Alternative check:

Gas-phase spectroscopy and standard chemistry references list oxygen as diatomic in its elemental gaseous form.

Why Other Options Are Wrong:

Values 4, 8, 16 misread the formula or confuse with atomic numbers/masses; “1” would be monatomic O, not the stable molecular form.

Common Pitfalls:

Confusing atomic mass (16) with atom count in a molecule; the former does not indicate the latter.

Final Answer:

2