Answer:
Oxygen - Proportions increased as plants released this gas into the atmosphere.
Water Vapor - Proportions decreased as this lighter gas was blown away by solar winds.
Hydrogen - Proportions increased as this gas was released through volcanic eruptions.
Ammonia - Proportions decreased as it reacted with other elements to form nitrogen.
Carbon Dioxide - Proportions decreases as plants used this gas during photosynthesis.
Global warming
Carbon dioxide is released into the air, causing global warming.
<span>Nitrate only. Niritate is anion.</span>
