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,
Compound modifier both (or all) of the words in a compound modifier are nouns, it is seen as not necessary to hyphenate them, as misunderstanding is unlikely. Japanese equivalents of adjectives can compound. This is quite common for "na"-adjectives, which function essentially as attributive noun phrases, while it is relatively uncommon for "i"-adjectives, and is much less common than Japanese compound verbs. Common examples include (noun + "i"-adjective) and ("i"-adjective stem + "i"-adjective). Compound modifier A compound modifier (also called a compound adjective, phrasal adjective, or adjectival phrase) is a compound of two or more attributive words: that is, two or more