Across
- 3. the development of this was important for the development of life on land
- 8. a type of plate boundary formed when plates reverse direction
- 9. the concept responsible for Earth's formation of layers
- 10. Earth's early atmosphere is thought to be similar to gases produced by these
- 13. this layer of the Earth creates a magnetic field, which protects the Earth from the Sun's harmful radiation and charged particles
- 15. this number tells us how many protons and neutrons are in the nucleus of an atom
- 16. how much time it takes a radioactive isotope to decay by one half
- 17. heat from the core of the Earth tranfers to the mantle, where this process takes plates that drives plate tectonics
Down
- 1. fossil evidence of early life on Earth that produced oxygen and changed Earth's atmosphere
- 2. the gas thought to be the most prevalent in Earth's early atmosphere
- 4. Earth's early oceans were formed from the outgassing of volcanoes as well as the bombardment of Earth by these
- 5. the Early Earth "grew" due to this process
- 6. the second most abundant gas in Earth's atmosphere
- 7. the presence of banded iron formations in the rocks from this era suggests that there was some oxygen present in the atmosphere
- 11. the first ocean water formed from this process that is part of the water cycle
- 12. along with hydrogen, formed Earth's earliest atmosphere
- 14. a type of seismic wave that can only pass through solids