Reply To: abbreviation in chemistry Home › Forums › Nemeth Code for Math and Science › abbreviation in chemistry › Reply To: abbreviation in chemistry September 12, 2009 at 10:21 am #20019 Chris ClemensKeymaster g and mol are abbreviations so the g would require the letter indicator. In Chemistry Code, letters and abbreviations are both punctuated mathematically, so you would use a punctuation indicator before the semicolon that follows g/mol.