Question

earths earliest atmosphere was composed of gases spewed from volcanoes. this atmosphere contains a very large percentage of
○ carbon dioxide
○ ozone
○ peroxide
○ oxygen

Explanation:

Earth's earliest atmosphere, formed from volcanic outgassing, had a high percentage of carbon dioxide. Volcanic eruptions release large amounts of \( \text{CO}_2 \), and early Earth's atmosphere lacked significant oxygen (ozone is related to oxygen and forms later, peroxide is not a major volcanic gas).

Answer:

A. Carbon dioxide