Carbon–hydrogen bond C−H bond is generally regarded as being non-polar. In structural formulas of molecules, the hydrogen atoms are often omitted. Compound classes consisting solely of C–H bonds and C–C bonds are alkanes, alkenes, alkynes, and aromatic hydrocarbons. Collectively they are known as hydrocarbons. In October 2016, astronomers reported that the very basic chemical ingredients of life—the carbon-hydrogen molecule (CH, or methylidyne radical), the carbon-hydrogen positive ion (CH+) and the carbon ion (C+)—are the result, in large part, of ultraviolet light from stars, rather than in other ways, such as the result of turbulent events related to supernovae and young stars, as
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