Include superscript & subscript in drop-down menu?

[earlsdon18]

I would like to include chemical formulas and powers of 10 in drop-down menus. I can change the whole of one option choice using 'style=' inside the <option...> tag . But I can't make individual characters super / sub-script. Any ideas please?

 

[earlsdon18]

Think I've got it for superscript 2 or 3:
Include control characters in the middle of the HTML between the <option> ... </option> tags.
e.g. <option>10&#178;</option> gives 10 with superscript 2.
Further control characters &#8308 to &#8313 give 4 to 9 but some spaces may be added.
Subscripts are &#8321 to 29
see

http://www.danshort.com/HTMLentities/index.php?w=super