Hypothetical chemical compound heat of formation ... can be used to determine whether a hypothetical compound is stable." However, "a negative formation enthalpy does not automatically imply the existence of a hypothetical compound." The method predicts that NaCl is stable but NeCl is not. It predicted XePtF based on the stability of OPtF. Hypothetical chemical compound A hypothetical chemical compound is a chemical compound that has been conceived of, but is not known to have been synthesized, observed, or isolated (identified or shown to exist). Some hypothetical compounds cannot form at all. Others might turn out to be highly unstable, decomposing, isomerizing, polymerizing,
Organic compound substance in Martian soil. Terrestrially, it, and its anhydride, mellitic anhydride, are associated with the mineral mellite (AlC(COO)·16HO). A slightly broader definition of organic compound includes all compounds bearing C-H or C-C bonds. This would still exclude urea. Moreover, this definition still leads to somewhat arbitrary divisions in sets of carbon-halogen compounds. For example, CF and CCl would be considered by this rule to be "inorganic", whereas CFH and CHCl would be organic, though these compounds share many physical and chemical properties. Organic compounds may be classified in a variety of ways. One major distinction is between natural and synthetic