Decrease separation between columns beamer

Question

I want to align an image with some text in a beamer frame. From what I've read on other questions, one way to do this is to use the command \begin{columns}. However, something is not formatted as I need it at the very end. This is my code and the frame created.

\begin{frame}
\frametitle{Motivación}
    \begin{columns}[onlytextwidth]
    \begin{column}{.48\textwidth}
        \begin{figure}[htp]
            \includegraphics[width=4cm]{frobenius.jpg}
            \caption{Ferdinand Georg Frobenius}
        \end{figure}
        \end{column}      
        \begin{column}{.48\textwidth}
            \justifying
            Ferdinand Georg Frobenius (26 October 1849 – 3 August 1917) was a German mathematician, best known for his contributions to the theory of elliptic functions, differential equations, number theory, and to group theory. 
        \end{column}
    \end{columns}
\end{frame} 

The right margin is very small and the text is very close to the end of the frame. I don't like this. I would like to either move the text a bit to the left or to make the margin bigger, but only in this frame. Can someone help me?

Edit I am using the Madrid theme and \usepackage{ragged2e} to justify text.

Answer 1

Your prescribed image width (4cm) is smaller then prescribed column width (0.58\textwidth ~ 48mm), consequently appears that column separation is large.

Distance between image and text you can reduce by defined width of image as \includegraphics[width=\linewidth]{example-image}. If resulted size of image is to big, you can reduce first column width to approximately to 0.44\linewidth (~ 4.2cm) and adequate increase width of the second column (to about 0.56\linewidth.

With this settings you will get:

MWE:

\documentclass{beamer}
\setbeamerfont{caption}{size=\footnotesize}

\begin{document}
\begin{frame}
\frametitle{Motivación}
    \begin{columns}[onlytextwidth]
    \begin{column}{.42\textwidth}
        \begin{figure}[htp]
            \includegraphics[width=\linewidth]{example-image-duck}%{frobenius.jpg}
            \caption{Ferdinand Georg Frobenius}
        \end{figure}
        \end{column}
        \begin{column}{.56\textwidth}
            %\justifying
            Ferdinand Georg Frobenius (26 October 1849 – 3 August 1917) was a German mathematician, best known for his contributions to the theory of elliptic functions, differential equations, number theory, and to group theory.
        \end{column}
    \end{columns}
\end{frame}
\end{document}

Note: please always provide MWE, a complete small document which we can compile as it is. By this you help us to help you.