Earth's Early Atmosphere (AQA GCSE Chemistry Combined Science): Flashcards

200 million years

First billion years of Earth's existence

Venus or Mars

Carbon dioxide ($\text{CO}_2$)

Very little to no oxygen

Water vapour ($\text{H}_2\text{O}$), methane ($\text{CH}_4$), ammonia ($\text{NH}_3$)

Volcanic activity

Millions of years

Oceans and seas

Released large amounts of gases into atmosphere