coalescence vs liquefaction

coalescence

noun
  • The act of coalescing. 

  • The merging of two segments into one. 

liquefaction

noun
  • The liquid or semiliquid that results from this process. 

  • Process of being, or state of having been, made liquid (from either a solid or a gas) 

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