most common chemical compound on earth
The most common compound on Earth is water. It's formula is H2O, meaning that in one water molecule, there are two hydrogen (H) atoms and one oxygen (O) atom.  Anoth â¦ er common compound is sodium chloride, which most people know as table salt.ydrogen is the most common atom in the universe, and oxygen is the thrid â¦ most common, so water has to be the number one compound.