We got MathJax enabled. Today I learned that there is even more! We could have support for Physical units enabled as part of the mhchem package! We use physical units a lot and demand the SI formatting. Let me quote from Worldbuilding:

Chemistry Stack Exchange is obviously the main consumer of this feature and has a nice FAQ on its use. The chemists get two things that we don't:

  • \require{mhchem} is implicit... you get support automatically without having to require it explicitly.
  • They get physical unit formatting via $\pu{273.15 K}$, which currently renders as a grumpy error on WB.SE and WB meta that looks [with only mhchem enabled] like this mathjax markup error

Can we have that too? Pretty please? I am tired of having to type $273.15\ \text{K}$ and such, especially if it is complex things in the unit!


2 Answers 2


I support this request for people that do want to use the support for physical units.

(vote up this answer if you are in favor)

For values and units I haven't used the MathJax notation (only for complex equations), I've always used the html characters for formatting values and units.

The example from the question would be written as:

273.15 K

which renders to "273.15 K"

or in Celsius:

0 °C

which renders to "0 °C".

The drawback of using the LaTeX style from MathJax (and presumably with mhchem support) is that the rendered value and unit are in a different font, for example:

Text rendering MathJax rendering MathJax code
273.15 K $273.15\ \text{K}$ $273.15\ \text{K}$
0 °C $0\ ^\text{o}\text{C}$ $0\ ^\text{o}\text{C}$ or $0\ ^\circ\text{C}$
  • $\begingroup$ mhchem also allows to write chemical fomulas and other things: $\ce{H2O}$ renders a very nice, non italicised $H_2O$ $\endgroup$
    – Trish
    Jun 8 at 13:03
  • $\begingroup$ Can't you put the \text before the number/quantity as well, so you get the same font? See this comment $\endgroup$
    – Greenonline Mod
    Jun 14 at 18:14

I do not support this request to support physical units.

(vote up this answer if you are not in favor)


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