Task: Text Categorization
Input (English): Many examples of this relationship involve components that may be separated by reaction with tartaric acid. This relationship, first discovered between cyanic and fulminic acid, may emerge when steric effects prevent a compound from rotating around otherwise freely rotating bonds. (*) Tautomers are rapidly interconverting examples of one form of this relationship. Another example of this relationship occurs between cis and trans examples of the same alkene, a type of diastereomerism (die-ah-STARE-ee-AH-mer-ism). Another example of this relationship, called "constitutional," exists between tert- and n-butane. For 10 points, name this relationship describing molecules with different structural formulas but the same molecular formula.
Output (English): Science