When atomic oxygen (O) comes into contact with substances that are already oxidized, what is the most likely outcome?

• A. Atomic oxygen will always form ozone (O_3) regardless of the substance it contacts.
• B. Atomic oxygen will reduce the oxidized substances back to their original state.
• C. Atomic oxygen will cause the substances to combust spontaneously.
• D. Atomic oxygen will have little to no effect, as the substances cannot be further oxidized.

Answer: (D)

Verified step by step guidance

1. Understand the nature of atomic oxygen (O). Atomic oxygen is a highly reactive species because it has unpaired electrons, making it a strong oxidizing agent.
2. Consider what it means for a substance to be 'already oxidized.' Such substances have already lost electrons or gained oxygen, so their oxidation state is relatively high.
3. Analyze the possible interactions: since the substances are already oxidized, atomic oxygen cannot further oxidize them significantly because oxidation involves loss of electrons or increase in oxidation state, which is limited once the substance is fully or highly oxidized.
4. Evaluate the given options: forming ozone (O_3) requires specific conditions and is not guaranteed just by contact with any oxidized substance; reduction would require atomic oxygen to gain electrons, which is unlikely; spontaneous combustion requires fuel and ignition conditions, not just atomic oxygen presence.
5. Conclude that atomic oxygen will have little to no effect on substances that are already oxidized because they cannot be further oxidized, making this the most chemically reasonable outcome.