Metastanic or Metastannic: How To spell?
The word Metastanic is misspelled against Metastannic, an adjective meaning "Pertaining to, or designating, a compound of tin (metastannic acid), obtained, as an isomeric modification of stannic acid, in the form of a white amorphous substance."
Metastannic has double "nn" is mispronounced as "n"Remember double 'NN' in between the strings metasta & ic which should not be misspelled with single 'N'
Wrong Spelling:  metasta-n-ic  Correct Spelling:  metasta-nn-ic 
Find more wrongly spelled words of Metastannic to spell it well.