i am really having a hard time. but i am sure that either KNO3 or CH3OH has the highest boiling point.
i don't know that should be prioritized, is it the intramolecular bonds or the Hbond.
also does an element like Ne, Fe, Kr and Cu have intermolecular bonds?
KNO3 is ionic K^+ NO3^- will have very high bp mp 334 °C bp = dec so poor question
CH3OH: Hydrogen bonding (NH, OH cmpds) bp 65 °C
C2H6: molecular nonpolar only weak London forces bp -89 °C
Ne; noble gas (you're not trying to make this a metal are you?) extremely weak London forces:
bp -246 °C
(I looked Wikipedia up for bps.)