fun size vs molecule

fun size

noun

  • A small size. 

adj

  • Small in size. 

molecule

noun

  • A tiny amount. 

  • The smallest particle of a specific element or compound that retains the chemical properties of that element or compound; two or more atoms held together by chemical bonds. 

How often have the words fun size and molecule occurred in a corpus of books? (source: Google Ngram Viewer )