Chemistry: Atoms in separate <mi> elements

[samimaattaCelia]

My point is that are different molecules elements on their own or is the individual atom the element? Should we mark up sodium chloride as <mi>NaCl</mi> or <mi>Na</mi><mi>Cl</mi> or even as text <mtext>NaCl</mtext>? I asked this same thing from Neil in the MathCAT repo, but he hasn't had time to answer yet.

I found some discussion on it in an old issue from w3c/mathml, where Neil shows that maybe the correct way would be to mark up <mi>Na</mi><mi>Cl</mi>.

MathML doesn't really concern itself with marking up chemistry and MathML 4 is the only one that even mentions chemistry at all.

Will this be difficult to test for and also to proofread?

[samimaattaCelia]

Some more chemistry related discussion from the MathJax example page on chemistry typesetting.

[samimaattaCelia]

Neil answered that it should be <mi>Na</mi><mi>Cl</mi>, because of two distinct elements.