A lot of the stuff in the universe is in elemental form, not in compounds (things made of two or more elements). The 10 most common elements are: Hydrogen; Helium; Oxygen; Neon; Nitrogen; Carbon; Silicon; Magnesium; Iron; Sulfur. read more
Carbon compounds such as graphite, coal, or diamonds are not found in living things. The confusion probably stems from the fact that carbon makes up a large portion of the elements in the DRY weight of living things. read more