-on
/ɒn/suffix Physics, Biochemistry, & Chemistry
Forming nouns:
1Denoting subatomic particles or quanta: neutron photon
2Denoting molecular units: codon
3Denoting substances: interferon
Origin
sense 1 originally in electron, from ion, influenced (as in sense 2) by Greek on 'being'; sense 3 is on the pattern of words such as cotton or from German -on.