What important change in the atmosphere occurred during the Proterozoic Eon?
A. Helium escaped into space and hydrogen was bound into water molecules
B. Nitrogen and carbon dioxide levels decreased, fueling bacteria growth
C. Carbon dioxide levels increased, causing glaciation that cooled the planet
D. Methane levels decreased and oxygen levels increased, promoting aerobic life forms
Answers: 1
Physics, 21.06.2019 21:00, Amandarobersonn
An electric current in a wire will push or pull on a permanent magnet. which statement best explains how an electric current creates an electromagnetic force on another magnet?
Answers: 2
Physics, 22.06.2019 04:00, mathnation1
If steel is more dense that lake water, why can a boat float
Answers: 1
Physics, 22.06.2019 08:30, mikemurray115
How is sound energy produced a. vibrating objects b. objects being heated c. temperature differences d. stationary objects
Answers: 2
What important change in the atmosphere occurred during the Proterozoic Eon?
A. Helium escaped int...
Mathematics, 30.04.2021 09:30
Mathematics, 30.04.2021 09:30
Mathematics, 30.04.2021 09:30
Mathematics, 30.04.2021 09:30
History, 30.04.2021 09:30
Mathematics, 30.04.2021 09:30