documentclass{article}
usepackage{amsmath,xcolor}
usepackage{tikz}
newcommand{tikznode}[2]{relax
ifmmode%
  tikz[remember picture,baseline=(#1.base),inner sep=0pt] node (#1) {$%tikznodestyle
  #2$};
else
  tikz[remember picture,baseline=(#1.base),inner sep=0pt] node (#1) {#2};%
fi}
begin{document}
 $tikznode{Al}{textcolor{cyan}{text{Al}}}^{tikznode{3p}{scriptstyle
 textcolor{cyan}{3+}}}
 quadtikznode{O}{textcolor{red}{text{O}}}^{tikznode{2m}{textcolor{red}{scriptstyle
2-}}}
 longrightarrow
 text{textcolor{cyan}{Al}}_{textcolor{red}{2}}textcolor{red}{text{O}}_{textcolor{cyan}{3}}$
 tikz[overlay,remember picture]{
 draw[-latex] (3p)--(O.south east);
 draw[-latex] (2m)--(Al.south east);
 }
end{document}