[javydog]

Is it possible to put superscript above subscript? I havent worked out a way, I was thinking i could just put them on either sides but then i have nowhere to put the charge if its an ion..

[AWK]

Try equation editor in text processor

[Borek]

There are many ways of formatting and many underlying technologies. Some of them don't allow combining the indices in a proper way. A lot depends on the software you are using and type of document you want to put the formula in.

LaTeX is quite flexible and was designed for this type of things:

[tex]^{137}_{\phantom{0}55}\mathrm{Cs} \rightarrow {}^{137}_{\phantom{0}56}\mathrm{Ba} + e^- + \bar{\nu}_e[/tex]

Unfortunately it is not always possible to incorporate LaTeX formulas in documents. When dealing with scientific paper it is often best to create them entirely in LaTeX, not just formulas.