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They realized that the known reversible reaction 2BaO (s) + O2 (g) ↔ 2BaO2 (s) was deactivated by the formation of barium carbonate from carbon dioxide in the air; treating air to remove the carbon …

Oxygen, or O2, is a colorless, odorless, and highly reactive gas that is essential for the survival of most living organisms on Earth. It is the second most abundant element in the Earth's atmosphere and …

Oxygen is a chemical element. It has the symbol O and atomic number 8. It is a colorless, odorless, and tasteless gas at 25 degrees Celsius at Standard atmosphere (a pressure). Oxygen is part of the air …

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O2 (brand), a global brand name owned by the Spanish telecommunications company Telefónica O2 Store, a chain of retail stores owned and operated by Telefónica Europe, with regional subsidiaries:

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