Step 2

Second, the core and the crust form. This happened because heavier particles sank while the lighter ones nestled on top of them. At the same time, even lighter elements formed the atmosphere and Earth's magnetic field formed. After this happened a huge asteroid collided head on with Earth making parts of the mantle traveled into space and, by gravity, the moon formed. The new flow of the mantle led to plate tectonics, which eventually led to a huge supercontinent called Pangea. All of the plate tectonics bumping into each other made mountains and volcanoes. From these landmarks, gases leaked into the atmosphere.