The Gaseous Oxygen in Earth's Atmosphere Was Produced as a By-Product

question 97

Multiple Choice

The gaseous oxygen in Earth's atmosphere was produced as a by-product of which process?

• A)Volcanic outgassing.
• B)Photochemical reactions breaking down ozone (O3)to form oxygen (O2).
• C)Photosynthesis.
• D)Decay of organic matter.

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