Question

how many % oxygen expired by human to the environment​

Answer 1

Answer:

After a human breathes in Earth's air (roughly 78 percent nitrogen and 21 percent oxygen), he or she exhales a mixture of compounds similar to the air inhaled: 78 percent nitrogen, 16 percent oxygen, 0.09 percent argon, and four percent carbon dioxide.

Explanation:

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Answer 2

Answer:

21% of oxygen

Explanation:

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