In a science test transcribed in Nemeth code (and EBAE) there are several chemistry questions. Am I correct to follow Chemistry code 3.5 and omit the ELI with chemical elements like N, but follow EBAE (not Chemistry code 9.1) and double cap abbreviations like DNA?
Neither the Chemistry Code nor the Nemeth Code says that you should omit the English letter indicator with the chemical SYMBOL "N" when it is not combined with any other letter, operator, or indicator. So, in a sentence like, "We use N as the symbol for nitrogen." the "N" should be preceded by an English letter indicator and a capital indicator.
As for "DNA," if you are transcribing in literary code or Nemeth (not Chemistry Code), DNA would be double-capped and punctuated according to EBAE.
So, in your NEMETH-EBAE transcription:
CO (the chemical SYMBOL, or formula, for carbon monoxide) would be ,c,o
DNA (the abbreviation for deoxyribonucleic acid) would be ,,dna
RNA (the abbreviation for ribonucleic acid) would be ,,rna
ATP (the abbreviation for adenosine triphosphate) would be ,,atp
S (the chemical SYMBOL for sulfur) would be ;,s