Carbon of interconnecting carbon–carbon bonds, a property that is called catenation. Carbon-carbon bonds are strong and stable. Through catenation, carbon forms a countless number of compounds. A tally of unique compounds shows that more contain carbon that those that do not. A similar claim can be made for hydrogen because most organic compounds also contain hydrogen. The simplest form of an organic molecule is the hydrocarbon—a large family of organic molecules that are composed of hydrogen atoms bonded to a chain of carbon atoms. A hydrocarbon backbone can be substituted by other atoms, known as heteroatoms. Common heteroatoms that appear in
Law of reciprocal proportions of multiple proportions. The law of definite proportions refers to the fixed composition of any compound formed between element A and element B. The law of multiple proportions describes the stoichiometric relationship between two or more different compounds formed between element A and element B. The law of reciprocal proportions was proposed in essence by Richter, following his determination of neutralisation ratios of metals with acids. In the early 19th century it was investigated by Berzelius, who formulated it as follows: Later Jean Stas showed that within experimental error the stoichiometric laws were correct. Law of reciprocal proportions The law