Carbon's ability to form carbon-to-carbon chains is one reason why carbon can form so many compounds. Carbon atoms can form chains, complex branches and rings. Carbon bonds with elements by sharing one, two or three electrons, which allows it to bond with a wide range of other atoms. Hydrogen is the most common element to bond with carbon, but nitrogen, oxygen, phosphorous, sulfur, and halogens, along with many other kinds of atoms, bond with carbon to form organic molecules. Learn more about Chemistry