Hydrogen
Helium is the first member and the most abundent element in the known universe
sodium and chlorine
Hydrogen at 71%
Mercury is the most iron-rich planet in the solar system.
Nitrogen is!
the second most abundent gas in the atmosphere is oxygen and the first in nitrogen
secret:)
flour
grass
Nitrogen
nitrogen
It's mostly iron (Fe) and nickel (Ni) down there. And it's molten, so it's real hot.