Abundance of the chemical elements in the Sun and outer planets is similar to that in the universe. Due to solar heating, the elements of Earth and the inner rocky planets of the Solar System have undergone an additional depletion of volatile hydrogen, helium, neon, nitrogen, and carbon (which volatilizes as methane). The crust, mantle, and core of the Earth show evidence of chemical segregation plus some sequestration by density. Lighter silicates of aluminum are found in the crust, with more magnesium silicate in the mantle, while metallic iron and nickel compose the core. The abundance of elements in specialized environments, such as atmospheres, or
Robin (Earth-Two) by standing by his mentor when Commissioner Wayne was under the influence of the Psycho-Pirate and agreeing to prosecute the Justice Society when Wayne's alleged diary surfaced. Robin developed resentment towards the Earth-One Batman during their first meeting after the original's death, which turned to grudging respect and finally acceptance. Previously, Robin showed a type of mentorship towards his younger counterpart, providing him a costume with elements he himself would eventually adopt. In the final issue of "52", a new Multiverse is revealed, originally consisting of 52 identical realities. Among the parallel realities shown is one designated "Earth-2." As a