Which statement best describes conditions on early Earth?
Meteor and asteroid impacts during Earth's creation and radiation from nearby supernova are all reasons for which characteristic of early Earth?
Which gas was in high concentrations in the early atmosphere, and later condensed to form Earth's oceans?
What gas was missing in Earth's early atmosphere?
The early Earth was so hot that it melted into magma. As it did so, the heaviest elements sank to the center and the lightest ones rose. What did the lightest elements form?