
\documentclass{article}
\usepackage{siunitx}
\pagestyle{empty}
\begin{document}
\noindent\SI{12}{\kilogram}\\
\SI{12}{\kilogram}\\
\SI{5.8}{\meter\per\second}\\
\SI{1.23}{\joule\per\mole\per\Kelvin}\\
\SI{15}{\electronvolt}\\
\SI{89}{\giga\pascal}\\
\SI{658.4}{\tera\hertz}\\
\SI{25}{\degreeCelsius}
\end{document}
