These numbers are the same. Carbon the most important element of life. Methane the simplest hydrocarbon. Molecular and structural formulas . Molecular formulas just show the composition of the molecules.
Structural formulas show what atoms are joined together.
Lewis structures are structural formulas. Double and triple bonds. Oxygene molecule O 2 and Ethylene C 2 H 4 . Protonation of ammonia Coordinate covalent bond covalent bond for which both shared electrons come from the same atom. Ammonia, chloride anion.