Gay-Lussac's law gases and the gaseous products can be expressed in simple whole numbers. For example, Gay-Lussac found that 2 volumes of hydrogen and 1 volume of oxygen would react to form 2 volumes of gaseous water. Based on Gay-Lussac's results, Amedeo Avogadro theorized that, at the same temperature and pressure, equal volumes of gas contain equal numbers of molecules (Avogadro's law). This hypothesis meant that the previously stated result could also be expressed as The law of combining gases was made public by Joseph Louis Gay-Lussac in 1808. Avogadro's hypothesis, however, was not initially accepted by chemists until the Italian chemist
Industrial gas since all isotopes are radiogenic nuclides from radioactive decay. (It is not known if any synthetic elements with atomic number above 108 are gases.) The elements which are stable two atom homonuclear molecules at standard temperature and pressure (STP), are hydrogen (H), nitrogen (N) and oxygen (O), plus the halogens fluorine (F) and chlorine (Cl). The noble gases are all monatomic. In the industrial gases industry the term "elemental gases" (or sometimes less accurately "molecular gases") is used to distinguish these gases from molecules that are also chemical compounds. These elements are all nonmetals. Radon is chemically stable, but it